From 3be85fe7ed694737ded136a2b43c105026b593d7 Mon Sep 17 00:00:00 2001
From: Jon Daniel <jondaniel879@gmail.com>
Date: Tue, 1 Aug 2023 18:31:54 +0200
Subject: [PATCH] fix TAR not loading

---
 CMakeLists.txt            |  9 +++++----
 src/physfs_archiver_tar.c | 32 ++++++++++++++------------------
 src/physfs_internal.h     |  8 ++++----
 src/physfs_tar.h          |  2 +-
 4 files changed, 24 insertions(+), 27 deletions(-)

diff --git a/CMakeLists.txt b/CMakeLists.txt
index aedafd1f..e366814e 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -126,15 +126,16 @@ if(NOT PHYSFS_ARCHIVE_WAD)
     add_definitions(-DPHYSFS_SUPPORTS_WAD=0)
 endif()
 
+option(PHYSFS_ARCHIVE_TAR "Enable POSIX TAR / Chasm: The Rift [Demo] Remastered csm.bin support" TRUE)
+if(NOT PHYSFS_ARCHIVE_TAR)
+    add_definitions(-DPHYSFS_SUPPORTS_TAR=0)
+endif()
+
 option(PHYSFS_ARCHIVE_CSM "Enable Chasm: The Rift CSM.BIN support" TRUE)
 if(NOT PHYSFS_ARCHIVE_CSM)
     add_definitions(-DPHYSFS_SUPPORTS_CSM=0)
 endif()
 
-option(PHYSFS_ARCHIVE_TAR "Enable POSIX TAR / Chasm: The Rift [Demo] Remastered csm.bin support" TRUE)
-if(NOT PHYSFS_ARCHIVE_TAR)
-    add_definitions(-DPHYSFS_SUPPORTS_TAR=0)
-endif()
 
 option(PHYSFS_ARCHIVE_HOG "Enable Descent I/II HOG support" TRUE)
 if(NOT PHYSFS_ARCHIVE_HOG)
diff --git a/src/physfs_archiver_tar.c b/src/physfs_archiver_tar.c
index 03dcab68..ac8f40c1 100644
--- a/src/physfs_archiver_tar.c
+++ b/src/physfs_archiver_tar.c
@@ -12,21 +12,18 @@
 #if PHYSFS_SUPPORTS_TAR
 #include "physfs_tar.h"
 
-static bool TAR_loadEntries(PHYSFS_Io *io, void *arc)
+static int TAR_loadEntries(PHYSFS_Io *io, void *arc)
 {
-	union block zero_block;
-	union block current_block;
+	union block zero_block = { 0 };
+	union block current_block = { 0 };
 	PHYSFS_uint64 count = 0;
 	bool long_name = false;
 
-	memset(zero_block.buffer, 0, sizeof(BLOCKSIZE));
-	memset(current_block.buffer, 0, sizeof(BLOCKSIZE));
-
 	/* read header block until zero-only terminated block */
-	for(; __PHYSFS_readAll(io, current_block.buffer, BLOCKSIZE); count++)
+	for(; __PHYSFS_readAll(io, current_block.buffer, BLOCKSIZE) != 0; count++)
 	{
 		if( memcmp(current_block.buffer, zero_block.buffer, BLOCKSIZE) == 0 )
-			return true;
+			return 1;
 
 		/* verify magic */
 		switch(TAR_magic(&current_block))
@@ -49,35 +46,34 @@ static bool TAR_loadEntries(PHYSFS_Io *io, void *arc)
 		}
 	}
 
-	return false;
+	return 0;
 }
 
 static void *TAR_openArchive(PHYSFS_Io *io, const char *name,
                               int forWriting, int *claimed)
 {
     void *unpkarc = NULL;
-    union block first;
-    enum archive_format format;
+    char buf[BLOCKSIZE] = { '\0' };
 
     assert(io != NULL);  /* shouldn't ever happen. */
 
     BAIL_IF(forWriting, PHYSFS_ERR_READ_ONLY, NULL);
+    BAIL_IF_ERRPASS(!__PHYSFS_readAll(io, buf, sizeof (buf)), NULL);
+    if ((memcmp(&buf[TMAGOFF], TMAGIC, TMAGLEN - 1) != 0) != 0)
+        BAIL(PHYSFS_ERR_UNSUPPORTED, NULL);
 
-    BAIL_IF_ERRPASS(!__PHYSFS_readAll(io, first.buffer, BLOCKSIZE), NULL);
-    format = TAR_magic(&first);
-    io->seek(io, 0);
-    *claimed = format == DEFAULT_FORMAT ? 0 : 1;
+    *claimed = 1;
 
-    unpkarc = UNPK_openArchive(io, 0, 1);
+    BAIL_IF_ERRPASS(!io->seek(io, 0), 0);
+    unpkarc = UNPK_openArchive(io, 1, 0);
     BAIL_IF_ERRPASS(!unpkarc, NULL);
 
-    if (!TAR_loadEntries(io, unpkarc))
+    if (TAR_loadEntries(io, unpkarc) == 0)
     {
         UNPK_abandonArchive(unpkarc);
         return NULL;
     } /* if */
 
-
     return unpkarc;
 } /* TAR_openArchive */
 
diff --git a/src/physfs_internal.h b/src/physfs_internal.h
index beff35d2..df1f5e50 100644
--- a/src/physfs_internal.h
+++ b/src/physfs_internal.h
@@ -88,8 +88,8 @@ extern const PHYSFS_Archiver __PHYSFS_Archiver_QPAK;
 extern const PHYSFS_Archiver __PHYSFS_Archiver_HOG;
 extern const PHYSFS_Archiver __PHYSFS_Archiver_MVL;
 extern const PHYSFS_Archiver __PHYSFS_Archiver_WAD;
-extern const PHYSFS_Archiver __PHYSFS_Archiver_CSM;
 extern const PHYSFS_Archiver __PHYSFS_Archiver_TAR;
+extern const PHYSFS_Archiver __PHYSFS_Archiver_CSM;
 extern const PHYSFS_Archiver __PHYSFS_Archiver_SLB;
 extern const PHYSFS_Archiver __PHYSFS_Archiver_ISO9660;
 extern const PHYSFS_Archiver __PHYSFS_Archiver_VDF;
@@ -202,12 +202,12 @@ void __PHYSFS_smallFree(void *ptr);
 #ifndef PHYSFS_SUPPORTS_WAD
 #define PHYSFS_SUPPORTS_WAD PHYSFS_SUPPORTS_DEFAULT
 #endif
-#ifndef PHYSFS_SUPPORTS_CSM
-#define PHYSFS_SUPPORTS_CSM PHYSFS_SUPPORTS_DEFAULT
-#endif
 #ifndef PHYSFS_SUPPORTS_TAR
 #define PHYSFS_SUPPORTS_TAR PHYSFS_SUPPORTS_DEFAULT
 #endif
+#ifndef PHYSFS_SUPPORTS_CSM
+#define PHYSFS_SUPPORTS_CSM PHYSFS_SUPPORTS_DEFAULT
+#endif
 #ifndef PHYSFS_SUPPORTS_QPAK
 #define PHYSFS_SUPPORTS_QPAK PHYSFS_SUPPORTS_DEFAULT
 #endif
diff --git a/src/physfs_tar.h b/src/physfs_tar.h
index 28da558c..dbc0092f 100644
--- a/src/physfs_tar.h
+++ b/src/physfs_tar.h
@@ -26,7 +26,7 @@
 #define TMAGIC   "ustar"          /* ustar and a null */
 #define OLDGNU_MAGIC "ustar  "	/* 7 chars and a null */
 #define TMAGLEN  6
-
+#define TMAGOFF 257
 #define TVERSION "00"             /* 00 and no null */
 #define TVERSLEN 2