From dd68246737bce01e9e76e8a5ed347db26a51f7dc Mon Sep 17 00:00:00 2001
From: "Ryan C. Gordon" <icculus@icculus.org>
Date: Sun, 13 Aug 2017 22:53:38 -0400
Subject: [PATCH] 7z: do global initialization once without risking a race
 condition.

---
 src/physfs.c             |  1 +
 src/physfs_archiver_7z.c | 21 +++++++++++++--------
 src/physfs_internal.h    |  5 +++++
 3 files changed, 19 insertions(+), 8 deletions(-)

diff --git a/src/physfs.c b/src/physfs.c
index e7872ffb..bac20d15 100644
--- a/src/physfs.c
+++ b/src/physfs.c
@@ -1143,6 +1143,7 @@ static int initStaticArchivers(void)
         REGISTER_STATIC_ARCHIVER(ZIP);
     #endif
     #if PHYSFS_SUPPORTS_7Z
+        SZIP_global_init();
         REGISTER_STATIC_ARCHIVER(7Z);
     #endif
     #if PHYSFS_SUPPORTS_GRP
diff --git a/src/physfs_archiver_7z.c b/src/physfs_archiver_7z.c
index 3099f355..be05d32d 100644
--- a/src/physfs_archiver_7z.c
+++ b/src/physfs_archiver_7z.c
@@ -217,14 +217,6 @@ static void *SZIP_openArchive(PHYSFS_Io *io, const char *name, int forWriting)
     SZIPinfo *info = NULL;
     SRes rc;
 
-    /* !!! FIXME-3.0: this is a race condition; we need a global init method that gets called when registering new archivers. */
-    static int generatedTable = 0;
-    if (!generatedTable)
-    {
-        generatedTable = 1;
-        CrcGenerateTable();
-    } /* if */
-
     BAIL_IF(forWriting, PHYSFS_ERR_READ_ONLY, NULL);
 
     info = (SZIPinfo *) allocator.Malloc(sizeof (SZIPinfo));
@@ -387,6 +379,19 @@ static int SZIP_stat(void *opaque, const char *path, PHYSFS_Stat *stat)
 } /* SZIP_stat */
 
 
+void SZIP_global_init(void)
+{
+    /* this just needs to calculate some things, so it only ever
+       has to run once, even after a deinit. */
+    static int generatedTable = 0;
+    if (!generatedTable)
+    {
+        generatedTable = 1;
+        CrcGenerateTable();
+    } /* if */
+} /* SZIP_global_init */
+
+
 const PHYSFS_Archiver __PHYSFS_Archiver_7Z =
 {
     CURRENT_PHYSFS_ARCHIVER_API_VERSION,
diff --git a/src/physfs_internal.h b/src/physfs_internal.h
index 636b0590..61463121 100644
--- a/src/physfs_internal.h
+++ b/src/physfs_internal.h
@@ -193,6 +193,11 @@ void __PHYSFS_smallFree(void *ptr);
 #define PHYSFS_SUPPORTS_VDF 1
 #endif
 
+#if PHYSFS_SUPPORTS_7Z
+/* 7zip support needs a global init function called at startup (no deinit). */
+extern void SZIP_global_init(void);
+#endif
+
 /* The latest supported PHYSFS_Io::version value. */
 #define CURRENT_PHYSFS_IO_API_VERSION 0