mojopatch.c

/*
 *----------------------------------------------------------------------------
 *
 * mojopatch
 * Copyright (C) 2003  Ryan C. Gordon.
 *
 *----------------------------------------------------------------------------
 *
 * (Insert documentation here.)
 *
 *----------------------------------------------------------------------------
 *
 *  This software was written quickly, is not well-engineered, and may have
 *   catastrophic bugs. Its method is brute-force, at best. Use at your
 *   own risk. Don't eat yellow snow.
 *
 *  Please see the file LICENSE in the root of the source tree.
 *
 *   Send patches, improvements, suggestions, etc to Ryan:
 *    icculus@clutteredmind.org.
 *
 *----------------------------------------------------------------------------
 */

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <stdarg.h>
#include <assert.h>
#include <errno.h>
#include <time.h>
#include <ctype.h>

#include "platform.h"
#include "ui.h"
#include "md5.h"

#define VERSION "0.0.5"

#define DEFAULT_PATCHFILENAME "default.mojopatch"

#define PATCHERROR    0
#define PATCHSUCCESS  1
#define MOJOPATCHSIG "mojopatch " VERSION " (icculus@clutteredmind.org)\r\n"

#define STATIC_STRING_SIZE 1024

static void make_static_string(char *statstr, const char *str)
{
    size_t len = strlen(str);
    if (len >= STATIC_STRING_SIZE)
        _fatal("Unexpected data in make_static_string()");
    else
        strcpy(statstr, str);
} /* make_static_string */


typedef struct
{
    char signature[sizeof (MOJOPATCHSIG)];
    char product[STATIC_STRING_SIZE];
    char identifier[STATIC_STRING_SIZE];
    char version[STATIC_STRING_SIZE];
    char newversion[STATIC_STRING_SIZE];
    char readmefname[STATIC_STRING_SIZE];
    char *readmedata;
    char renamedir[STATIC_STRING_SIZE];
    char titlebar[STATIC_STRING_SIZE];
} PatchHeader;

typedef enum
{
    OPERATION_DELETE = 0,
    OPERATION_DELETEDIRECTORY,
    OPERATION_ADD,
    OPERATION_ADDDIRECTORY,
    OPERATION_PATCH,
    OPERATION_REPLACE,
    OPERATION_DONE,
    OPERATION_TOTAL /* must be last! */
} OperationType;

typedef struct
{
    OperationType operation;
    char fname[STATIC_STRING_SIZE];
} DeleteOperation;

typedef struct
{
    OperationType operation;
    char fname[STATIC_STRING_SIZE];
} DeleteDirOperation;

typedef struct
{
    OperationType operation;
    char fname[STATIC_STRING_SIZE];
    size_t fsize;
    md5_byte_t md5[16];
    mode_t mode;
} AddOperation;

typedef struct
{
    OperationType operation;
    char fname[STATIC_STRING_SIZE];
    mode_t mode;
} AddDirOperation;

typedef struct
{
    OperationType operation;
    char fname[STATIC_STRING_SIZE];
    md5_byte_t md5_1[16];
    md5_byte_t md5_2[16];
    size_t fsize;
    size_t deltasize;
    mode_t mode;
} PatchOperation;

typedef struct
{
    OperationType operation;
} DoneOperation;

typedef union
{
    OperationType operation;
    DeleteOperation del;
    DeleteDirOperation deldir;
    AddOperation add;
    AddDirOperation adddir;
    PatchOperation patch;
    AddOperation replace;
    DoneOperation done;
} Operations;

typedef struct
{
    FILE *io;
    int reading;
} SerialArchive;

typedef enum
{
    COMMAND_NONE = 0,
    COMMAND_CREATE,
    COMMAND_INFO,
    COMMAND_DOPATCHING,

    COMMAND_TOTAL
} PatchCommands;


static int debug = 0;
static int interactive = 0;
static int replace = 0;
static PatchCommands command = COMMAND_NONE;

static const char *patchfile = NULL;
static const char *dir1 = NULL;
static const char *dir2 = NULL;

static char *patchtmpfile = NULL;
static char *patchtmpfile2 = NULL;

static PatchHeader header;

static char **ignorelist = NULL;
static int ignorecount = 0;

static unsigned int maxxdeltamem = 128;  /* in megabytes. */

static unsigned char iobuf[512 * 1024];


static int serialize(SerialArchive *ar, void *val, size_t size)
{
    int rc;
    if (ar->reading)
        rc = fread(val, size, 1, ar->io);
    else
        rc = fwrite(val, size, 1, ar->io);

    if (rc <= 0)
    {
        _fatal("%s error: %s.", ar->reading ? "Read":"Write", strerror(errno));
        return(0);
    } /* if */

    return(1);
} /* serialize */


#define SERIALIZE(ar, x) serialize(ar, &x, sizeof (x))

static int serialize_static_string(SerialArchive *ar, char *val)
{
    size_t len;

    if (!SERIALIZE(ar, len))
        return(0);

    if (len >= STATIC_STRING_SIZE)
    {
        _fatal("Bogus string data in patchfile.");
        return(0);
    } /* if */

    val[len] = 0;
    return(serialize(ar, &val, len));
} /* serialize_static_string */


/*
 * This will only overwrite (val)'s contents if (val) is empty ("!val[0]").
 *  Mostly, this lets us optionally override patchfiles from the command line.
 *  Writing is done, regardless of string's state.
 */
static int serialize_static_string_if_empty(SerialArchive *ar, char *val)
{
    if ((!ar->reading) || (val[0] == '\0'))
        return(serialize_static_string(ar, val));
    else
    {
        char buffer[STATIC_STRING_SIZE];
        return(serialize_static_string(ar, buffer));  /* throw away data */
    } /* else */
} /* serialize_static_string_if_empty */


static int serialize_asciz_string(SerialArchive *ar, char **_buffer)
{
    char *buffer = *_buffer;
    size_t i = 0;
    size_t allocated = 0;
    int ch;

    if (!ar->reading)
        return(serialize(ar, buffer, strlen(buffer) + 1));

    buffer = NULL;

    /* read an arbitrary amount, allocate storage... */
    do
    {
        if (i <= allocated)
        {
            allocated += 128;
            buffer = realloc(buffer, allocated);
            if (buffer == NULL)
            {
                _fatal("Out of memory.");
                return(0);
            } /* if */
        } /* if */

        ch = fgetc(ar->io);
        if (ch == EOF)
        {
            if (feof(ar->io))
                _fatal("Unexpected EOF during read.");
            else
                _fatal("Error during read: %s.", strerror(errno));
            return(PATCHERROR);
        } /* if */

        buffer[i] = (char) ch;
    } while (buffer[i++] != '\0');

    *_buffer = buffer;
    return(1);
} /* serialize_asciz_string */


static int serialize_header(SerialArchive *ar, PatchHeader *h)
{
    if (!SERIALIZE(ar, h->signature))
        return(0);

    if (memcmp(h->signature, MOJOPATCHSIG, sizeof (h->signature)) != 0)
    {
        h->signature[sizeof (h->signature) - 1] = '\0';  /* just in case. */
        _fatal("[%s] is not a compatible mojopatch file.", patchfile);
        _log("signature is: %s.", h->signature);
        _log("    expected: %s.", MOJOPATCHSIG);
        return(PATCHERROR);
    } /* if */

    if (serialize_static_string_if_empty(ar, h->product))
    if (serialize_static_string_if_empty(ar, h->identifier))
    if (serialize_static_string_if_empty(ar, h->version))
    if (serialize_static_string_if_empty(ar, h->newversion))
    if (serialize_static_string_if_empty(ar, h->readmefname))
    if (serialize_asciz_string(ar, &h->readmedata))
    if (serialize_static_string_if_empty(ar, h->renamedir))
    if (serialize_static_string_if_empty(ar, h->titlebar))
        return(1);

    return(0);
} /* serialize_header */

static int serialize_delete_op(SerialArchive *ar, void *d)
{
    DeleteOperation *del = (DeleteOperation *) d;
    assert(del->operation == OPERATION_DELETE);
    if (serialize_static_string(ar, del->fname))
        return(1);

    return(0);
} /* serialize_delete_op */

static int serialize_deldir_op(SerialArchive *ar, void *d)
{
    DeleteDirOperation *deldir = (DeleteDirOperation *) d;
    assert(deldir->operation == OPERATION_DELETEDIRECTORY);
    if (serialize_static_string(ar, deldir->fname))
        return(1);

    return(0);
} /* serialize_deldir_op */

static int serialize_add_op(SerialArchive *ar, void *d)
{
    AddOperation *add = (AddOperation *) d;
    assert((add->operation == OPERATION_ADD) ||
           (add->operation == OPERATION_REPLACE));
    if (serialize_static_string(ar, add->fname))
    if (SERIALIZE(ar, add->fsize))
    if (SERIALIZE(ar, add->md5))
    if (SERIALIZE(ar, add->mode))
        return(1);

    return(0);
} /* serialize_add_op */

static int serialize_adddir_op(SerialArchive *ar, void *d)
{
    AddDirOperation *adddir = (AddDirOperation *) d;
    assert(adddir->operation == OPERATION_ADDDIRECTORY);
    if (serialize_static_string(ar, adddir->fname))
    if (SERIALIZE(ar, adddir->mode))
        return(1);

    return(0);
} /* serialize_adddir_op */

static int serialize_patch_op(SerialArchive *ar, void *d)
{
    PatchOperation *patch = (PatchOperation *) d;
    assert(patch->operation == OPERATION_PATCH);
    if (serialize_static_string(ar, patch->fname))
    if (SERIALIZE(ar, patch->md5_1))
    if (SERIALIZE(ar, patch->md5_1))
    if (SERIALIZE(ar, patch->fsize))
    if (SERIALIZE(ar, patch->deltasize))
    if (SERIALIZE(ar, patch->mode))
        return(1);

    return(0);
} /* serialize_patch_op */

static int serialize_replace_op(SerialArchive *ar, void *d)
{
    AddOperation *add = (AddOperation *) d;
    assert(add->operation == OPERATION_REPLACE);
    return(serialize_add_op(ar, d));
} /* serialize_replace_op */

static int serialize_done_op(SerialArchive *ar, void *d)
{
    DoneOperation *done = (DoneOperation *) d;
    assert(done->operation == OPERATION_DONE);
    return(1);
} /* serialize_done_op */


typedef int (*OpSerializers)(SerialArchive *ar, void *data);
static OpSerializers serializers[OPERATION_TOTAL] =
{
    /* Must match OperationType order! */
    serialize_delete_op,
    serialize_deldir_op,
    serialize_add_op,
    serialize_adddir_op,
    serialize_patch_op,
    serialize_replace_op,
    serialize_done_op,
};


static int handle_delete_op(SerialArchive *ar, OperationType op, void *data);
static int handle_deldir_op(SerialArchive *ar, OperationType op, void *data);
static int handle_add_op(SerialArchive *ar, OperationType op, void *data);
static int handle_adddir_op(SerialArchive *ar, OperationType op, void *data);
static int handle_patch_op(SerialArchive *ar, OperationType op, void *data);
static int handle_replace_op(SerialArchive *ar, OperationType op, void *data);

typedef int (*OpHandlers)(SerialArchive *ar, OperationType op, void *data);
static OpHandlers operation_handlers[OPERATION_TOTAL] =
{
    /* Must match OperationType order! */
    handle_delete_op,
    handle_deldir_op,
    handle_add_op,
    handle_adddir_op,
    handle_patch_op,
    handle_replace_op,
};


static int serialize_operation(SerialArchive *ar, Operations *ops)
{
    if (!SERIALIZE(ar, ops->operation))
        return(0);

    if ((ops->operation < 0) || (ops->operation >= OPERATION_TOTAL))
    {
        _fatal("Invalid operation in patch file.");
        return(0);
    } /* if */

    return(serializers[ops->operation](ar, &ops));
} /* serialize_operation */


static int open_serialized_archive(SerialArchive *ar,
                                   const char *fname,
                                   int is_reading,
                                   int *sizeok,
                                   size_t *file_size)
{
    memset(ar, '\0', sizeof (*ar));
    if (strcmp(fname, "-") == 0)  /* read from stdin? */
        ar->io = (is_reading) ? stdin : stdout;
    else
	{
        if (file_size != NULL)
        {
            int tmp = get_file_size(patchfile, file_size);
            if (sizeok != NULL)
                *sizeok = tmp;
        } /* if */

        ar->io = fopen(patchfile, is_reading ? "rb" : "wb");
        if (ar->io == NULL)
        {
            _fatal("Couldn't open [%s]: %s.", patchfile, strerror(errno));
            return(PATCHERROR);
        } /* if */
	} /* else */

    ar->reading = is_reading;
    return(PATCHSUCCESS);
} /* open_serialized_archive */


static inline int close_serialized_archive(SerialArchive *ar)
{
    if (ar->io != NULL)
    {
        if (fclose(ar->io) == EOF)
            return(PATCHERROR);

        ar->io = NULL;
    } /* if */

    return(PATCHSUCCESS);
} /* close_serialized_archive */


/* printf-style: makes string for UI to put in the log. */
void _fatal(const char *fmt, ...)
{
    char buf[512];
    va_list ap;
    va_start(ap, fmt);
    vsnprintf(buf, sizeof (buf), fmt, ap);
    va_end(ap);
    buf[sizeof(buf)-1] = '\0';
    ui_fatal(buf);
    ui_pump();
} /* _fatal */

/* printf-style: makes string for UI to put in the log. */
void _log(const char *fmt, ...)
{
    char buf[512];
    va_list ap;
    va_start(ap, fmt);
    vsnprintf(buf, sizeof (buf), fmt, ap);
    va_end(ap);
    buf[sizeof(buf)-1] = '\0';
    ui_add_to_log(buf, 0);
    ui_pump();
} /* _log */


/* printf-style: makes string for UI to put in the log if debugging enabled. */
void _dlog(const char *fmt, ...)
{
    if (debug)
    {
        char buf[512];
        va_list ap;
        va_start(ap, fmt);
        vsnprintf(buf, sizeof (buf), fmt, ap);
        va_end(ap);
        buf[sizeof(buf)-1] = '\0';
        ui_add_to_log(buf, 1);
        ui_pump();
    } /* if */
} /* _dlog */

static void _current_operation(const char *fmt, ...)
{
    char buf[512];
    va_list ap;
    va_start(ap, fmt);
    vsnprintf(buf, sizeof (buf), fmt, ap);
    va_end(ap);
    buf[sizeof(buf)-1] = '\0';
    ui_status(buf);
    ui_pump();
} /* _current_operation */


/* don't taunt this function. */
int version_ok(const char *ver, const char *allowed_ver)
{
    char *ptr;
    char *buf = (char *) alloca(strlen(allowed_ver) + 1);
    strcpy(buf, allowed_ver);

    while ((ptr = strstr(buf, " or ")) != NULL)
    {
        *ptr = '\0';
        if (strcmp(ver, buf) == 0)
            return(1);

        buf = ptr + 4;
    } /* while */

    return(strcmp(ver, buf) == 0);
} /* version_ok */


static int _do_xdelta(const char *fmt, ...)
{
    char buf[512];
    va_list ap;
    va_start(ap, fmt);
    vsnprintf(buf, sizeof (buf), fmt, ap);
    va_end(ap);
    buf[sizeof(buf)-1] = '\0';
	_dlog("(xdelta call: [%s].)", buf);
    return(spawn_xdelta(buf));
} /* _do_xdelta */


static int in_ignore_list(const char *fname)
{
    int i;
    for (i = 0; i < ignorecount; i++)
    {
        if (strcmp(fname, ignorelist[i]) == 0)
        {
            _log("Ignoring %s on user's instructions.", fname);
            return(1);
        } /* if */
    } /* for */

    return(0);
} /* in_ignore_list */


static inline int info_only(void)
{
    return(command == COMMAND_INFO);
} /* info_only */


static void free_filelist(file_list *list)
{
    file_list *next;
    while (list != NULL)
    {
        next = list->next;
        free(list->fname);
        free(list);
        list = next;
    } /* while */
} /* free_filelist */


static int write_between_files(FILE *in, FILE *out, long fsize)
{
    while (fsize > 0)
    {
        int max = sizeof (iobuf);
        if (max > fsize)
            max = fsize;

        int br = fread(iobuf, 1, max, in);
        if (br <= 0)
        {
            _fatal("read error: %s.", strerror(errno));
            return(PATCHERROR);
        } /* if */
        ui_pump();

        if (fwrite(iobuf, br, 1, out) != 1)
        {
            _fatal("write error: %s.", strerror(errno));
            return(PATCHERROR);
        } /* if */
        ui_pump();

        fsize -= br;
    } /* while */

    return(PATCHSUCCESS);
} /* write_between_files */


static int do_rename(const char *from, const char *to)
{
    FILE *in;
    FILE *out;
    long fsize;
    int rc;

    unlink(to);  /* just in case. */
    if (rename(from, to) != -1)
        return(PATCHSUCCESS);

    /* rename() might fail if from and to are on seperate filesystems. */

    rc = get_file_size(from, &fsize);
    in = fopen(from, "rb");
    out = fopen(to, "wb");
    if ((!rc) || (!in) || (!out))
    {
        if (in)
            fclose(in);
        if (out)
            fclose(out);
        unlink(to);
        _fatal("File copy failed.");
        return(PATCHERROR);
    } /* if */

    rc = write_between_files(in, out, fsize);

    fclose(in);
    if ((fclose(out) == -1) && (rc != PATCHERROR))
    {
        _fatal("File copy failed.");
        return(PATCHERROR);
    } /* if */

    unlink(from);

    return(rc);
} /* do_rename */


static int md5sum(FILE *in, md5_byte_t *digest, int output)
{
    md5_state_t md5state;
    long br;

    _dlog("md5summing...");

    memset(digest, '\0', 16);
    md5_init(&md5state);

    if (fseek(in, 0, SEEK_SET) == -1)
    {
        _fatal("Couldn't seek in file: %s.", strerror(errno));
        return(PATCHERROR);
    } /* if */

    while (1)
    {
        ui_pump();

        br = fread(iobuf, 1, sizeof (iobuf), in);
        if (br == 0)
        {
            int err = errno;
            if (feof(in))
                break;
            else
            {
                _fatal("Read error: %s.", strerror(err));
                return(PATCHERROR);
            } /* else */
        } /* if */
        md5_append(&md5state, (const md5_byte_t *) iobuf, br);
    } /* while */

    md5_finish(&md5state, digest);

    if ((output) || (debug))
    {
      /* ugly, but want to print it all on one line... */
        _log("  (md5sum: %02x%02x%02x%02x%02x%02x%02x%02x%02x%02x%02x%02x%02x%02x%02x%02x)",
              digest[0],  digest[1],  digest[2],  digest[3],
              digest[4],  digest[5],  digest[6],  digest[7],
              digest[8],  digest[9],  digest[10], digest[11],
              digest[12], digest[13], digest[14], digest[15]);
    } /* if */

    if (fseek(in, 0, SEEK_SET) == -1)
    {
        _fatal("Couldn't seek in file: %s.", strerror(errno));
        return(PATCHERROR);
    } /* if */

    return(PATCHSUCCESS);
} /* md5sum */


static int verify_md5sum(md5_byte_t *md5, md5_byte_t *result, FILE *in, int isfatal)
{
    md5_byte_t thismd5[16];

    if (md5sum(in, thismd5, 0) == PATCHERROR)
        return(PATCHERROR);

    if (result != NULL)
		memcpy(result, thismd5, sizeof (thismd5));

    if (memcmp(thismd5, md5, sizeof (thismd5)) != 0)
    {
        if (isfatal)
            _fatal("md5sum doesn't match original!");
        return(PATCHERROR);
    } /* if */
    
    return(PATCHSUCCESS);
} /* verify_md5sum */


/* !!! FIXME: This should be in the UI abstraction. */
static int confirm(void)
{
    char buf[256];
    char *ptr;

    if (!interactive)
        return(1);

    while (1)
    {
        printf("Confirm [Y/n] : ");
        fgets(buf, sizeof (buf) - 1, stdin);
        if ( (ptr = strchr(buf, '\r')) != NULL )
            *ptr = '\0';
        if ( (ptr = strchr(buf, '\n')) != NULL )
            *ptr = '\0';

        if (strlen(buf) <= 1)
        {
            int ch = tolower((int) buf[0]);
            if ((ch == '\0') || (ch == 'y'))
            {
                printf("Answered YES\n");
                return(1);
            } /* if */
            else if (ch == 'n')
            {
                printf("Answered NO\n");
                return(0);
            } /* else if */
        } /* if */
    } /* while */
} /* confirm */


static const char *final_path_element(const char *fname)
{
    const char *ptr = (const char *) strrchr(fname, PATH_SEP[0]);
    assert( (sizeof (PATH_SEP)) == (sizeof (char) * 2) );
    return(ptr ? ptr + 1 : fname);
} /* final_path_element */


/* put a DELETE operation in the mojopatch file... */
static int put_delete(SerialArchive *ar, const char *fname)
{
    DeleteOperation del;

    _current_operation("DELETE %s", final_path_element(fname));
    _log("DELETE %s", fname);

    if (in_ignore_list(fname))
        return(PATCHSUCCESS);

    if (!confirm())
        return(PATCHSUCCESS);

    del.operation = OPERATION_DELETE;
    make_static_string(del.fname, fname);
    return(serialize_delete_op(ar, &del));
} /* put_delete */


/* get a DELETE operation from the mojopatch file... */
static int handle_delete_op(SerialArchive *ar, OperationType op, void *d)
{
    DeleteOperation *del = (DeleteOperation *) d;
    assert(op == OPERATION_DELETEDIRECTORY);

    _current_operation("DELETE %s", final_path_element(del->fname));
    _log("DELETE %s", del->fname);

    if ( (info_only()) || (!confirm()) )
        return(PATCHSUCCESS);

    if (in_ignore_list(del->fname))
        return(PATCHSUCCESS);

    if (!file_exists(del->fname))
    {
        _log("file seems to be gone already.");
        return(PATCHSUCCESS);
    } /* if */

    if (file_is_directory(del->fname))
    {
        _fatal("Expected file, found directory!");
        return(PATCHERROR);
    } /* if */

    if (remove(del->fname) == -1)
    {
        _fatal("Error removing [%s]: %s.", del->fname, strerror(errno));
        return(PATCHERROR);
    } /* if */

    _log("done DELETE.");
    return(PATCHSUCCESS);
} /* handle_delete_op */


/* put a DELETEDIRECTORY operation in the mojopatch file... */
static int put_delete_dir(SerialArchive *ar, const char *fname)
{
    DeleteDirOperation deldir;

    _current_operation("DELETEDIRECTORY %s", final_path_element(fname));
    _log("DELETEDIRECTORY %s", fname);

    if (!confirm())
        return(PATCHSUCCESS);

    if (in_ignore_list(fname))
        return(PATCHSUCCESS);

    deldir.operation = OPERATION_DELETEDIRECTORY;
    make_static_string(deldir.fname, fname);
    return(serialize_delete_op(ar, &deldir));
} /* put_delete_dir */


static int delete_dir_tree(const char *fname)
{
    char filebuf[MAX_PATH];
    file_list *files = make_filelist(fname);
    file_list *i;
    int rc = 0;

    _log("Deleting directory tree %s", fname);

    for (i = files; i != NULL; i = i->next)
    {
        snprintf(filebuf, sizeof (filebuf), "%s%s%s", fname, PATH_SEP, i->fname);
        if (file_is_directory(filebuf))
            rc = delete_dir_tree(filebuf);
        else
        {
            _log("Deleting file %s from dir tree", filebuf);
            rc = (remove(filebuf) == -1) ? PATCHERROR : PATCHSUCCESS;
            if (rc == PATCHERROR)
                _fatal("failed to delete %s: %s.", filebuf, strerror(errno));
        } /* else */

        if (rc == PATCHERROR)
        {
            free_filelist(files);
            return(PATCHERROR);
        } /* if */
    } /* for */

    free_filelist(files);

    if (rmdir(fname) == -1)
    {
        _fatal("Error removing directory [%s]: %s.", fname, strerror(errno));
        return(PATCHERROR);
    } /* if */

    return(PATCHSUCCESS);
} /* delete_dir_tree */


/* get a DELETEDIRECTORY operation from the mojopatch file... */
static int handle_deldir_op(SerialArchive *ar, OperationType op, void *d)
{
    DeleteDirOperation *deldir = (DeleteDirOperation *) d;
    assert(op == OPERATION_DELETEDIRECTORY);

    _current_operation("DELETEDIRECTORY %s", final_path_element(deldir->fname));
    _log("DELETEDIRECTORY %s", deldir->fname);

    if ( (info_only()) || (!confirm()) )
        return(PATCHSUCCESS);

    if (in_ignore_list(deldir->fname))
        return(PATCHSUCCESS);

    if (!file_exists(deldir->fname))
    {
        _log("directory seems to be gone already.");
        return(PATCHSUCCESS);
    } /* if */

    if (!file_is_directory(deldir->fname))
    {
        _fatal("Expected directory, found file!");
        return(PATCHERROR);
    } /* if */

    if (!delete_dir_tree(deldir->fname))
        return(PATCHERROR);

    _log("done DELETEDIRECTORY.");
    return(PATCHSUCCESS);
} /* handle_deldir_op */


/* put an ADD operation in the mojopatch file... */
static int put_add(SerialArchive *ar, const char *fname)
{
    AddOperation add;
    FILE *in = NULL;
    struct stat statbuf;
    int retval = PATCHERROR;

    _current_operation("%s %s", (replace) ? "ADDORREPLACE" : "ADD",
                        final_path_element(fname));
    _log("%s %s", (replace) ? "ADDORREPLACE" : "ADD", fname);

    if (!confirm())
        return(PATCHSUCCESS);

    if (in_ignore_list(fname))
        return(PATCHSUCCESS);

    if (stat(fname, &statbuf) == -1)
    {
        _fatal("Couldn't stat %s: %s.", fname, strerror(errno));
        return(PATCHERROR);
    } /* if */

    in = fopen(fname, "rb");
    if (in == NULL)
    {
        _fatal("failed to open [%s]: %s.", fname, strerror(errno));
        return(PATCHERROR);
    } /* if */

    if (md5sum(in, add.md5, debug) == PATCHERROR)
        goto put_add_done;

    add.operation = (replace) ? OPERATION_REPLACE : OPERATION_ADD;
    add.fsize = statbuf.st_size;
    add.mode = (mode_t) statbuf.st_mode;
    make_static_string(add.fname, fname);

    if (!serialize_add_op(ar, &add))
        goto put_add_done;

    if (!write_between_files(in, ar->io, add.fsize))
        goto put_add_done;

    assert(fgetc(in) == EOF);
    retval = PATCHSUCCESS;

put_add_done:
    if (in != NULL)
        fclose(in);
    return(retval);
} /* put_add */


/* get an ADD or REPLACE operation from the mojopatch file... */
static int handle_add_op(SerialArchive *ar, OperationType op, void *d)
{
    AddOperation *add = (AddOperation *) d;
    assert((op == OPERATION_ADD) || (op == OPERATION_REPLACE));
    int replace_ok = (op == OPERATION_REPLACE);
    int retval = PATCHERROR;
    FILE *io = NULL;
    int rc;

    _current_operation("%s %s", (replace_ok) ? "ADDORREPLACE" : "ADD",
                          final_path_element(add->fname));
    _log("%s %s", (replace_ok) ? "ADDORREPLACE" : "ADD", add->fname);

    if ( (info_only()) || (!confirm()) || (in_ignore_list(add->fname)) )
    {
        if (fseek(ar->io, add->fsize, SEEK_CUR) < 0)
        {
            _fatal("Seek error: %s.", strerror(errno));
            return(PATCHERROR);
        } /* if */
        return(PATCHSUCCESS);
    } /* if */

    if (file_exists(add->fname))
    {
        if (replace_ok)
            unlink(add->fname);
        else
        {
            if (file_is_directory(add->fname))
            {
                _fatal("Error: [%s] already exists, but it's a directory!", add->fname);
                return(PATCHERROR);
            } /* if */

            _log("[%s] already exists...looking at md5sum...", add->fname);
            _current_operation("VERIFY %s", final_path_element(add->fname));
            io = fopen(add->fname, "rb");
            if (io == NULL)
            {
                _fatal("Failed to open added file for read: %s.", strerror(errno));
                goto handle_add_done;
            } /* if */
        
            if (verify_md5sum(add->md5, NULL, io, 1) == PATCHERROR)
                goto handle_add_done;

            _log("Okay; file matches what we expected.");
            fclose(io);

            if (fseek(ar->io, add->fsize, SEEK_CUR) < 0)
            {
                _fatal("Seek error: %s.", strerror(errno));
                return(PATCHERROR);
            } /* if */

            return(PATCHSUCCESS);
        } /* else */
    } /* if */

    io = fopen(add->fname, "wb");
    if (io == NULL)
    {
        _fatal("Error creating [%s]: %s.", add->fname, strerror(errno));
        goto handle_add_done;
    } /* if */

    rc = write_between_files(ar->io, io, add->fsize);
    if (rc == PATCHERROR)
        goto handle_add_done;

    if (fclose(io) == EOF)
    {
        _fatal("Error: Couldn't flush output: %s.", strerror(errno));
        goto handle_add_done;
    } /* if */

    chmod(add->fname, add->mode);  /* !!! FIXME: Should this be an error condition? */

    _current_operation("VERIFY %s", final_path_element(add->fname));
    io = fopen(add->fname, "rb");
    if (io == NULL)
    {
        _fatal("Failed to open added file for read: %s.", strerror(errno));
        goto handle_add_done;
    } /* if */
        
    if (verify_md5sum(add->md5, NULL, io, 1) == PATCHERROR)
        goto handle_add_done;

    retval = PATCHSUCCESS;
    _log("done %s.", (replace_ok) ? "ADDORREPLACE" : "ADD");

handle_add_done:
    if (io != NULL)
        fclose(io);

    return(retval);
} /* handle_add_op */


static int handle_replace_op(SerialArchive *ar, OperationType op, void *d)
{
    assert(op == OPERATION_REPLACE);
    return(handle_add_op(ar, op, d));
} /* handle_replace_op */


static int put_add_for_wholedir(SerialArchive *ar, const char *base);


/* put an ADDDIRECTORY operation in the mojopatch file... */
static int put_add_dir(SerialArchive *ar, const char *fname)
{
    AddDirOperation adddir;
    struct stat statbuf;

    _current_operation("ADDDIRECTORY %s", final_path_element(fname));
    _log("ADDDIRECTORY %s", fname);

    if (!confirm())
        return(PATCHSUCCESS);

    if (in_ignore_list(fname))
        return(PATCHSUCCESS);

    if (stat(fname, &statbuf) == -1)
    {
        _fatal("Couldn't stat %s: %s.", fname, strerror(errno));
        return(PATCHERROR);
    } /* if */

    adddir.operation = OPERATION_ADDDIRECTORY;
    adddir.mode = (mode_t) statbuf.st_mode;
    make_static_string(adddir.fname, fname);

    if (!serialize_adddir_op(ar, &adddir))
        return(PATCHERROR);

    /* must add contents of dir after dir itself... */
    if (put_add_for_wholedir(ar, fname) == PATCHERROR)
        return(PATCHERROR);

    return(PATCHSUCCESS);
} /* put_add_dir */


/* get an ADDDIRECTORY operation from the mojopatch file... */
static int handle_adddir_op(SerialArchive *ar, OperationType op, void *d)
{
    AddDirOperation *adddir = (AddDirOperation *) d;
    assert(op == OPERATION_ADDDIRECTORY);
    
    _current_operation("ADDDIRECTORY %s", final_path_element(adddir->fname));
    _log("ADDDIRECTORY %s", adddir->fname);

    if ( (info_only()) || (!confirm()) || (in_ignore_list(adddir->fname)) )
        return(PATCHSUCCESS);

    if (file_exists(adddir->fname))
    {
        if (file_is_directory(adddir->fname))
        {
            _log("[%s] already exists.", adddir->fname);
            return(PATCHSUCCESS);
        } /* if */
        else
        {
            _fatal("[%s] already exists, but it's a file!", adddir->fname);
            return(PATCHERROR);
        } /* else */
    } /* if */

    if (mkdir(adddir->fname, S_IRWXU) == -1)
    {
        _fatal("Error making directory [%s]: %s.", adddir->fname, strerror(errno));
        return(PATCHERROR);
    } /* if */

    /* !!! FIXME: Pass this to mkdir? */
    chmod(adddir->fname, adddir->mode);  /* !!! FIXME: Should this be an error condition? */

    _log("done ADDDIRECTORY.");
    return(PATCHSUCCESS);
} /* handle_adddir_op */


/* put add operations for each file in (base). Recurses into subdirs. */
static int put_add_for_wholedir(SerialArchive *ar, const char *base)
{
    char filebuf[MAX_PATH];
    file_list *files = make_filelist(base);
    file_list *i;
    int rc = 0;

    for (i = files; i != NULL; i = i->next)
    {
        snprintf(filebuf, sizeof (filebuf), "%s%s%s", base, PATH_SEP, i->fname);

        /* put_add_dir recurses back into this function. */
        if (file_is_directory(filebuf))
            rc = put_add_dir(ar, filebuf);
        else
            rc = put_add(ar, filebuf);

        if (rc == PATCHERROR)
        {
            free_filelist(files);
            return(PATCHERROR);
        } /* if */
    } /* for */

    free_filelist(files);
    return(PATCHSUCCESS);
} /* put_add_for_wholedir */


static int md5sums_match(const char *fname1, const char *fname2,
                         md5_byte_t *md5_1, md5_byte_t *md5_2)
{
    FILE *in;

    in = fopen(fname1, "rb");
    if (in == NULL)
        return(0);

    if (md5sum(in, md5_1, 0) == PATCHERROR)
        return(0);

    fclose(in);

    in = fopen(fname2, "rb");
    if (in == NULL)
        return(0);

    if (md5sum(in, md5_2, 0) == PATCHERROR)
        return(0);

    fclose(in);

    return(memcmp(md5_1, md5_2, 16) == 0);
} /* md5sums_match */


/* put a PATCH operation in the mojopatch file... */
static int put_patch(SerialArchive *ar, const char *fname1, const char *fname2)
{
    PatchOperation patch;
    FILE *deltaio = NULL;
    int retval = PATCHERROR;
    struct stat statbuf;

    _current_operation("VERIFY %s", final_path_element(fname2));
	if (md5sums_match(fname1, fname2, patch.md5_1, patch.md5_2))
        return(PATCHSUCCESS);

    _current_operation("PATCH %s", final_path_element(fname2));
    _log("PATCH %s", fname2);

    if (!confirm())
        return(PATCHSUCCESS);

    if (in_ignore_list(fname2))
        return(PATCHSUCCESS);

    if (stat(fname2, &statbuf) == -1)
    {
        _fatal("Couldn't stat %s: %s.", fname2, strerror(errno));
        return(PATCHERROR);
    } /* if */

    if ( (!_do_xdelta("delta -n --maxmem=%dM \"%s\" \"%s\" \"%s\"", maxxdeltamem, fname1, fname2, patchtmpfile)) ||
         (!get_file_size(patchtmpfile, &patch.deltasize)) )
    {
        /* !!! FIXME: Not necessarily true. */
        _fatal("there was a problem running xdelta.");
        return(PATCHERROR);
    } /* if */

    patch.operation = OPERATION_PATCH;
    patch.mode = (mode_t) statbuf.st_mode;
    patch.fsize = statbuf.st_size;
    make_static_string(patch.fname, fname2);
    if (!serialize_patch_op(ar, &patch))
        return(PATCHERROR);

    deltaio = fopen(patchtmpfile, "rb");
    if (deltaio == NULL)
    {
        _fatal("couldn't read %s: %s.", patchtmpfile, strerror(errno));
        return(PATCHERROR);
    } /* if */

    retval = write_between_files(deltaio, ar->io, patch.deltasize);
    assert(fgetc(deltaio) == EOF);
    fclose(deltaio);
    unlink(patchtmpfile);
    return(retval);
} /* put_patch */


/* get a PATCH operation from the mojopatch file... */
static int handle_patch_op(SerialArchive *ar, OperationType op, void *d)
{
    PatchOperation *patch = (PatchOperation *) d;
	md5_byte_t md5result[16];
    FILE *f = NULL;
    FILE *deltaio = NULL;
    int rc;

    assert(op == OPERATION_PATCH);

    _log("PATCH %s", patch->fname);

    if ( (info_only()) || (!confirm()) || (in_ignore_list(patch->fname)) )
    {
        if (fseek(ar->io, patch->deltasize, SEEK_CUR) < 0)
        {
            _fatal("Seek error: %s.", strerror(errno));
            return(PATCHERROR);
        } /* if */
        return(PATCHSUCCESS);
    } /* if */

    f = fopen(patch->fname, "rb");
    if (f == NULL)
    {
        _fatal("Failed to open [%s]: %s.", patch->fname, strerror(errno));
        return(PATCHERROR);
    } /* if */

    _current_operation("VERIFY %s", final_path_element(patch->fname));
    rc = verify_md5sum(patch->md5_1, md5result, f, 0);
    fclose(f);
    if (rc == PATCHERROR)
    {
        if (memcmp(patch->md5_2, md5result, sizeof (patch->md5_2)) == 0)
        {
            _log("Okay; file matches patched md5sum. It's already patched.");
            if (fseek(ar->io, patch->deltasize, SEEK_CUR) < 0)
            {
                _fatal("Seek error: %s.", strerror(errno));
                return(PATCHERROR);
            } /* if */
            return(PATCHSUCCESS);
        } /* if */
        return(PATCHERROR);
    } /* if */

    unlink(patchtmpfile2); /* just in case... */

    _current_operation("PATCH %s", final_path_element(patch->fname));
    deltaio = fopen(patchtmpfile2, "wb");
    if (deltaio == NULL)
    {
        _fatal("Failed to open [%s]: %s.", patchtmpfile2, strerror(errno));
        return(PATCHERROR);
    } /* if */

    rc = write_between_files(ar->io, deltaio, patch->deltasize);
    fclose(deltaio);
    if (rc == PATCHERROR)
    {
        unlink(patchtmpfile2);
        return(PATCHERROR);
    } /* if */

    if (!_do_xdelta("patch --maxmem=%dM \"%s\" \"%s\" \"%s\"", maxxdeltamem, patchtmpfile2, patch->fname, patchtmpfile))
    {
        _fatal("xdelta failed.");
        return(PATCHERROR);
    } /* if */

    unlink(patchtmpfile2);  /* ditch temp delta file... */

    f = fopen(patchtmpfile, "rb");
    if (f == NULL)
    {
        _fatal("Failed to open [%s] for read: %s.", patchtmpfile, strerror(errno));
        return(PATCHERROR);
    } /* if */

    _current_operation("VERIFY %s", final_path_element(patch->fname));
    rc = verify_md5sum(patch->md5_2, NULL, f, 1);
    fclose(f);
    if (rc == PATCHERROR)
        return(PATCHERROR);

    if (do_rename(patchtmpfile, patch->fname) == -1)
    {
        _fatal("Error replacing [%s] with tempfile: %s.", patch->fname, strerror(errno));
        return(PATCHERROR);
    } /* if */

    chmod(patch->fname, patch->mode);  /* !!! FIXME: fatal error? */

    _log("done PATCH.");
    return(PATCHSUCCESS);
} /* handle_patch_op */


static int compare_directories(SerialArchive *ar,
                               const char *base1,
                               const char *base2)
{
    int retval = PATCHERROR;
    char filebuf1[MAX_PATH];
    char filebuf2[MAX_PATH]; /* can you feel the stack screaming? */
    const char *base2checked = *base2 ? base2 : ".";
    file_list *files1 = make_filelist(base1);
    file_list *files2 = NULL;
    file_list *i;

    /* may be recursive compare on deleted dir. */
    if (file_exists(base2checked))
        files2 = make_filelist(base2checked);

    assert(*base1);

    _current_operation("Examining %s", final_path_element(base2checked));
    _dlog("Examining %s and %s", base1, base2checked);

    _dlog("(looking for files that need deletion...)");

    /* check for files removed in newer version... */
    for (i = files1; i != NULL; i = i->next)
    {
        _dlog("([%s]...)", i->fname);

        snprintf(filebuf2, sizeof (filebuf2), "%s%s%s", base2,
                    *base2 ? PATH_SEP : "", i->fname);

        if (!file_exists(filebuf2))
        {
            int rc = 0;

            snprintf(filebuf1, sizeof (filebuf1), "%s%s%s", base1, PATH_SEP, i->fname);
            if (!file_is_directory(filebuf1))
                rc = put_delete(ar, filebuf2);
            else
            {
                rc = compare_directories(ar, filebuf1, filebuf2);
                if (rc != PATCHERROR)
                    rc = put_delete_dir(ar, filebuf2);
            } /* else */

            if (rc == PATCHERROR)
                goto dircompare_done;
        } /* if */
    } /* for */

    _dlog("(looking for files that need addition...)");

	/* check for files added in newer version... */
    for (i = files2; i != NULL; i = i->next)
    {
        _dlog("([%s]...)", i->fname);

        snprintf(filebuf1, sizeof (filebuf1), "%s%s%s", base1, PATH_SEP, i->fname);
        snprintf(filebuf2, sizeof (filebuf2), "%s%s%s", base2,
                    *base2 ? PATH_SEP : "", i->fname);

        if (file_exists(filebuf1))  /* exists in both dirs; do compare. */
        {
            if (file_is_directory(filebuf2))
            {
                    /* probably a bad sign ... */
                if (!file_is_directory(filebuf1))
                {
                    _log("%s is a directory, but %s is not!", filebuf2, filebuf1);
                    if (put_delete(ar, filebuf2) == PATCHERROR)
                        goto dircompare_done;

                    if (put_add_dir(ar, filebuf2) == PATCHERROR)
                        goto dircompare_done;
                } /* if */

                if (compare_directories(ar, filebuf1, filebuf2) == PATCHERROR)
                    goto dircompare_done;
            } /* if */

            else  /* new item is not a directory. */
            {
                    /* probably a bad sign ... */
                if (file_is_directory(filebuf1))
                {
                    _log("Warning: %s is a directory, but %s is not!", filebuf1, filebuf2);
                    if (put_delete_dir(ar, filebuf2) == PATCHERROR)
                        goto dircompare_done;

                    if (put_add(ar, filebuf2) == PATCHERROR)
                        goto dircompare_done;
                } /* if */

                else
                {
                    /* may not put anything if files match... */
                    if (put_patch(ar, filebuf1, filebuf2) == PATCHERROR)
                        goto dircompare_done;
                } /* else */
            } /* else */
        } /* if */

        else  /* doesn't exist in second dir; do add. */
        {
            if (file_is_directory(filebuf2))
            {
                if (put_add_dir(ar, filebuf2) == PATCHERROR)
                    goto dircompare_done;
            } /* if */

            else
            {
                if (put_add(ar, filebuf2) == PATCHERROR)
                    goto dircompare_done;
            } /* else */
        } /* else */
    } /* for */

    retval = PATCHSUCCESS;

dircompare_done:
    free_filelist(files1);
    free_filelist(files2);
    return(retval);
} /* compare_directories */


static char *read_whole_file(const char *fname)
{
    int i;
    int rc;
    FILE *io = NULL;
    long fsize = 0;
    char *retval = NULL;

    if (!get_file_size(fname, &fsize))
    {
        _fatal("Can't get filesize for [%s]...file missing?", fname);
        return(NULL);
    } /* if */

    if ( (retval = (char *) malloc(fsize + 1)) == NULL )
    {
        _fatal("Out of memory.");
        return(NULL);
    } /* if */

    if ( (io = fopen(fname, "r")) == NULL )
    {
        _fatal("Can't open [%s].", fname);
        free(retval);
        return(NULL);
    } /* if */

    rc = fread(retval, fsize, 1, io);
    fclose(io);

    if (rc != 1)
    {
        _fatal("Read on [%s] failed: %s", fname, strerror(errno));
        free(retval);
        return(NULL);
    } /* if */

    /* This considers it an error condition to have a null char in the file. */
    for (i = 0; i < fsize; i++)
    {
        if (retval[i] == '\0')
        {
            _fatal("null char in read_whole_file.");
            free(retval);
            return(NULL);
        } /* if */
    } /* for */
    retval[fsize] = '\0';

    return(retval);
} /* read_whole_file */


static int create_patchfile(void)
{
    SerialArchive ar;
    int retval = PATCHSUCCESS;
    size_t fsize;
    char *real1 = NULL;
    char *real2 = NULL;
    char *real3 = NULL;
    char *readmefull = NULL;

    if (header.readmefname[0])  /* user specified a README? */
    {
        const char *ptr = NULL;
        readmefull = alloca(strlen(header.readmefname) + 1);

        /* header stores filename, not path. Chop it out, but retain orig. */
        strcpy(readmefull, header.readmefname);
        ptr = final_path_element(readmefull);
        if (ptr != readmefull)
            make_static_string(header.readmefname, ptr);
    } /* if */

    if (strcmp(header.identifier, "") == 0) /* specified on the commandline. */
    {
        ui_fatal("Can't create a patchfile without an identifier.");
        return(PATCHERROR);
    } /* if */

    // !!! FIXME: platform should determine this by examining compared dirs.
    if (strcmp(header.version, "") == 0)  /* specified on the commandline. */
    {
        ui_fatal("Can't create a patchfile without --version.");
        return(PATCHERROR);
    } /* if */

    // !!! FIXME: platform should determine this by examining compared dirs.
    if (strcmp(header.newversion, "") == 0)  /* specified on the commandline. */
    {
        ui_fatal("Can't create a patchfile without --newversion.");
        return(PATCHERROR);
    } /* if */

    real1 = get_realpath(dir1);
    if (real1 == NULL)
    {
        _fatal("Couldn't get realpath of [%s].", dir1);
        return(PATCHERROR);
    } /* if */

    real2 = get_realpath(dir2);
    if (real2 == NULL)
    {
        _fatal("Couldn't get realpath of [%s].", dir2);
        return(PATCHERROR);
    } /* if */

    real3 = get_realpath(patchfile);
    if (real3 == NULL)
    {
        _fatal("Couldn't get realpath of [%s].", patchfile);
        return(PATCHERROR);
    } /* if */

    unlink(patchfile);  /* just in case. */

    if (!open_serialized_archive(&ar, patchfile, 0, NULL, NULL))
    {
        free(real1);
        free(real2);
        free(real3);
        _fatal("Couldn't open [%s]: %s.", patchfile, strerror(errno));
        return(PATCHERROR);
    } /* if */

    if (chdir(real2) != 0)
    {
        close_serialized_archive(&ar);
        free(real1);
        free(real2);
        free(real3);
        _fatal("Couldn't chdir to [%s]: %s.", real2, strerror(errno));
        return(PATCHERROR);
    } /* if */
    free(real2);

    if (readmefull != NULL)
    {
        header.readmedata = read_whole_file(readmefull);
        if (!header.readmedata)
        {
            close_serialized_archive(&ar);
            free(real1);
            free(real3);
            return(PATCHERROR);
        } /* if */
    } /* if */
    else
    {
        header.readmedata = malloc(1);  /* bleh. */
        header.readmedata[0] = '\0';
    } /* else */

    if (!serialize_header(&ar, &header))
    {
        close_serialized_archive(&ar);
        free(real1);
        free(real3);
        free(header.readmedata);
        return(PATCHERROR);
    } /* if */

    free(header.readmedata);

    retval = compare_directories(&ar, real1, "");

    free(real1);

    if (retval != PATCHERROR)
    {
        DoneOperation done;
        done.operation = OPERATION_DONE;
        retval = serialize_done_op(&ar, &done) ? PATCHSUCCESS : PATCHERROR;
    } /* if */

    if (!close_serialized_archive(&ar))
    {
        free(real3);
        _fatal("Couldn't close [%s]: %s.", patchfile, strerror(errno));
        retval = PATCHERROR;
    } /* if */

    if (!get_file_size(real3, &fsize))
    {
        _fatal("Couldn't get size of [%s]: %s.", patchfile, strerror(errno));
        retval = PATCHERROR;
    } /* if */
    free(real3);

    if (retval == PATCHERROR)
        _fatal("THE FILE [%s] IS LIKELY INCOMPLETE. DO NOT USE!", patchfile);
    else
    {
        ui_success("Patchfile successfully created.");
        _log("%ld bytes in the file [%s].", fsize, patchfile);
    } /* else */

    return(retval);
} /* create_patchfile */


static int do_patch_operations(SerialArchive *ar,
                               int do_progress,
                               long patchfile_size)
{
    Operations ops;
    memset(&ops, '\0', sizeof (ops));

    if (info_only())
        _log("These are the operations we would perform if patching...");

    do
    {
        ui_pump();

        if (do_progress)
        {
            long pos = ftell(ar->io);
            int progress = (int) (((float)pos)/((float)patchfile_size)*100.0f);
            ui_total_progress((pos == -1) ? -1 : progress);
        } /* if */

        if (!serialize_operation(ar, &ops))
            return(PATCHERROR);

        assert((ops.operation >= 0) && (ops.operation < OPERATION_TOTAL));
        if (!operation_handlers[ops.operation](ar, ops.operation, &ops))
            return(PATCHERROR);
    } while (ops.operation != OPERATION_DONE);

    return(PATCHSUCCESS);
} /* do_patch_operations */


static int process_patch_header(SerialArchive *ar, PatchHeader *h)
{
    int retval = PATCHSUCCESS;

    _log("Product to patch: \"%s\".", *h->product ? h->product : "(blank)");
    _log("Product identifier: \"%s\".", h->identifier);
    _log("Patch from version: \"%s\".", h->version);
    _log("Patch to version: \"%s\".", h->newversion);
    _log("Readme: \"%s\".", *h->readmefname ? h->readmefname : "(none)");
    _log("Renamedir: \"%s\".", *h->renamedir ? h->renamedir : "(none)");
    _log("UI titlebar: \"%s\".", *h->titlebar ? h->titlebar : "(blank)");

    /* Fill in a default titlebar if needed. */
    if (*h->titlebar == '\0')
    {
        if (*h->product != '\0')
            make_static_string(h->titlebar, h->product);
        else
        {
            char defstr[128];
            snprintf(defstr, sizeof (defstr) - 1, "MojoPatch %s", VERSION);
            make_static_string(h->titlebar, defstr);
        } /* else */
        _dlog("Defaulted UI titlebar to [%s].", h->titlebar);
    } /* if */

    ui_title(h->titlebar);

    if (!info_only())
    {
        if (!chdir_by_identifier(h->identifier, h->version))
            return(PATCHERROR);
    } /* if */

    if (h->readmedata)
    {
        if (!info_only())
            retval = show_and_install_readme(h->readmefname, h->readmedata);
        free(h->readmedata);
        h->readmedata = NULL;
    } /* if */

    return(retval);
} /* process_patch_header */


static int do_patching(void)
{
    SerialArchive ar;
    int report_error = 0;
    int retval = PATCHERROR;
    long file_size = 0;  /* !!! FIXME: make this size_t? */
    int do_progress = 0;

    ui_total_progress(do_progress ? 0 : -1);
    ui_pump();

    if (!open_serialized_archive(&ar, patchfile, 1, &do_progress, &file_size))
        return(PATCHERROR);

    if (!serialize_header(&ar, &header))
        goto do_patching_done;

    if (process_patch_header(&ar, &header) == PATCHERROR)
        goto do_patching_done;

    report_error = 1;
    if (file_size == 0)
        do_progress = 0;  /* prevent a division by zero. */
    if (do_patch_operations(&ar, do_progress, file_size) == PATCHERROR)
        goto do_patching_done;

    close_serialized_archive(&ar);

    if (!info_only())
    {
        _current_operation("Updating product version...");
        ui_total_progress(-1);
        if ( (*header.newversion) && (!update_version(header.newversion)) )
            goto do_patching_done;

        if (*header.renamedir)
        {
            char cwdbuf[MAX_PATH];
            if (getcwd(cwdbuf, sizeof (cwdbuf)) != NULL)
            {
                chdir("..");
                rename(cwdbuf, header.renamedir);
                chdir(header.renamedir);  /* just in case */
            } /* if */
        } /* if */
    } /* if */

    retval = PATCHSUCCESS;
    ui_total_progress(100);
    if (!info_only())
        ui_success("Patching successful!");

do_patching_done:
    close_serialized_archive(&ar);

    if ((retval == PATCHERROR) && (report_error))
    {
        ui_total_progress(-1);
        _fatal("There were problems, so I'm aborting.");
        if (!info_only())
            _fatal("The product is possibly damaged and requires a fresh installation.");
    } /* if */

    return(retval);
} /* do_patching */


static int do_usage(const char *argv0)
{
    _log("");
    _log("USAGE: %s --create <file.mojopatch> <dir1> <dir2>", argv0);
    _log("   or: %s --info <file.mojopatch>", argv0);
    _log("   or: %s <file.mojopatch>", argv0);
    _log("");
    _log("  You may also specify:");
    _log("      --product (Product name)");
    _log("      --identifier (Product identifier for locating installation)");
    _log("      --version (Product version to patch against)");
    _log("      --newversion (Product version to patch up to)");
    _log("      --replace (AT CREATE TIME, specify ADDs can overwrite)");
    _log("      --readme (README filename to display/install)");
    _log("      --renamedir (What patched dir should be called)");
    _log("      --titlebar (What UI's window's titlebar should say)");
    _log("      --ignore (Ignore specific files/dirs)");
    _log("      --confirm (Make process confirm each step)");
    _log("      --debug (spew debugging output)");
    _log("");
    return(0);
} /* do_usage */


static int set_command_or_abort(PatchCommands cmd)
{
    if (command != COMMAND_NONE)
    {
        _fatal("You've specified more than one command!");
        return(0);
    } /* if */

    command = cmd;
    return(1);
} /* set_command_or_abort */


static int parse_cmdline(int argc, char **argv)
{
    int i;
    int nonoptcount = 0;
    char **nonoptions = (char **) alloca(sizeof (char *) * argc);

    if (nonoptions == NULL)
    {
        _fatal("Out of memory!");
        return(0);
    } /* if */

    if (argc <= 1)
    {
        if (file_exists(DEFAULT_PATCHFILENAME))
            nonoptions[nonoptcount++] = DEFAULT_PATCHFILENAME;
        else
            return(do_usage(argv[0]));
    } /* if */

    for (i = 1; i < argc; i++)
    {
        int okay = 1;

        if (strncmp(argv[i], "--", 2) != 0)
        {
            nonoptions[nonoptcount++] = argv[i];
            continue;
        } /* if */

        if (strcmp(argv[i], "--create") == 0)
            okay = set_command_or_abort(COMMAND_CREATE);
        else if (strcmp(argv[i], "--info") == 0)
            okay = set_command_or_abort(COMMAND_INFO);
        else if (strcmp(argv[i], "--confirm") == 0)
            interactive = 1;
        else if (strcmp(argv[i], "--debug") == 0)
            debug = 1;
        else if (strcmp(argv[i], "--replace") == 0)
            replace = 1;
        else if (strcmp(argv[i], "--product") == 0)
            make_static_string(header.product, argv[++i]);
        else if (strcmp(argv[i], "--identifier") == 0)
            make_static_string(header.identifier, argv[++i]);
        else if (strcmp(argv[i], "--version") == 0)
            make_static_string(header.version, argv[++i]);
        else if (strcmp(argv[i], "--newversion") == 0)
            make_static_string(header.newversion, argv[++i]);
        else if (strcmp(argv[i], "--readme") == 0)
            make_static_string(header.readmefname, argv[++i]);
        else if (strcmp(argv[i], "--renamedir") == 0)
            make_static_string(header.renamedir, argv[++i]);
        else if (strcmp(argv[i], "--titlebar") == 0)
            make_static_string(header.titlebar, argv[++i]);
        else if (strcmp(argv[i], "--ignore") == 0)
        {
            ignorecount++;
            ignorelist = (char **) realloc(ignorelist, sizeof (char *) * ignorecount);
            // !!! FIXME: Check retval.
            ignorelist[ignorecount-1] = argv[++i];
        } /* else if */
        else
        {
            _fatal("Error: Unknown option [%s].", argv[i]);
            return(do_usage(argv[0]));
        } /* else */

        if (!okay)
            return(0);
    } /* for */

    if (command == COMMAND_NONE)
        command = COMMAND_DOPATCHING;

    switch (command)
    {
        case COMMAND_INFO:
        case COMMAND_DOPATCHING:
            if (nonoptcount != 1)
            {
                _fatal("Error: Wrong arguments.");
                return(do_usage(argv[0]));
            } /* if */
            patchfile = nonoptions[0];
            break;

        case COMMAND_CREATE:
            if (nonoptcount != 3)
            {
                _fatal("Error: Wrong arguments.");
                return(do_usage(argv[0]));
            } /* if */
                
            patchfile = nonoptions[0];
            dir1 = nonoptions[1];
            dir2 = nonoptions[2];
            break;

        default:
            assert(0);
            break;
    } /* switch */

    if (debug)
    {
        _dlog("debugging enabled.");
        _dlog("Interactive mode %senabled.", (interactive) ? "" : "NOT ");
        _dlog("ADDs are %spermitted to REPLACE.", (replace) ? "" : "NOT ");
        _dlog("command == (%d).", (int) command);
        _dlog("(%d) nonoptions:", nonoptcount);
        for (i = 0; i < nonoptcount; i++)
            _dlog(" [%s]", nonoptions[i]);
        _dlog("patchfile == [%s].", (patchfile) ? patchfile : "(null)");
        _dlog("dir1 == [%s].", (dir1) ? dir1 : "(null)");
        _dlog("dir2 == [%s].", (dir2) ? dir2 : "(null)");
        for (i = 0; i < ignorecount; i++)
            _dlog("ignoring [%s].", ignorelist[i]);
    } /* if */

    return(1);
} /* parse_cmdline */


/* !!! FIXME: signal_cleanup */


int mojopatch_main(int argc, char **argv)
{
	time_t starttime = time(NULL);
    int retval = PATCHSUCCESS;

    memset(&header, '\0', sizeof (header));

    if (!ui_init())
    {
        _fatal("MojoPatch: ui_init() failed!");  /* oh well. */
        return(PATCHERROR);
    } /* if */

    _log("MojoPatch %s starting up.", VERSION);

    if (!parse_cmdline(argc, argv))
    {
        ui_deinit();
        return(PATCHERROR);
    } /* if */

    if (!calc_tmp_filenames(&patchtmpfile, &patchtmpfile2))
    {
        _fatal("Internal error: Couldn't find scratch filenames.");
        ui_deinit();
        return(PATCHERROR);
    } /* if */
    _dlog("Temp filenames are [%s] and [%s].", patchtmpfile, patchtmpfile2);

    if (command == COMMAND_CREATE)
        retval = create_patchfile();
    else
        retval = do_patching();

    unlink(patchtmpfile);  /* just in case. */
    unlink(patchtmpfile2); /* just in case. */

    _dlog("(Total running time: %ld seconds.)", time(NULL) - starttime);

    ui_deinit();
    return(retval);
} /* mojopatch_main */

/* end of mojopatch.c ... */