.fixed potential memory issue when loading CD game after a large ROM file

.added support for upper-case ROM file extensions
.modified load_archive behavior so that it does not overwrite original filename with uncompressed name anymore
.replaced use of strcmp by memcmp

source/genesis.c

@@ -348,7 +348,7 @@ void gen_tmss_w(unsigned int offset, unsigned int data)
   WRITE_WORD(tmss, offset, data);
 
   /* VDP requires "SEGA" value to be written in TMSS register */
-  if (strncmp((char *)tmss, "SEGA", 4) == 0)
+  if (memcmp((char *)tmss, "SEGA", 4) == 0)
   {
     for (i=0xc0; i<0xe0; i+=8)
     {

source/gx/config.c

@@ -61,7 +61,7 @@ static int config_load(void)
     char version[16];
     fseek(fp, 0, SEEK_SET);
     fread(version, 16, 1, fp);
-    if (strncmp(version,CONFIG_VERSION,16))
+    if (memcmp(version,CONFIG_VERSION,16))
     {
       fclose(fp);
       return 0;

source/gx/fileio/fileio.c

@@ -83,37 +83,7 @@ static inline u16 FLIP16 (u16 b)
   return c;
 }
 
-void get_zipfilename(char *filename)
+int load_archive(char *filename, unsigned char *buffer, int maxsize, char *extension)
-{
-  char in[CHUNKSIZE];
-
-  /* Open file */
-  FILE *fd = fopen(filename, "rb");
-  if (!fd) return;
-
-  /* Read first 2 bytes  */
-  fread(in, 2, 1, fd);
-
-  /* Detect Zip file */
-  if (memcmp(in, "PK", 2) == 0)
-  {
-    /* Read remaining header data */
-    fread(in + 2, sizeof(PKZIPHEADER) - 2, 1, fd);
-
-    /* Zip header pointer */
-    PKZIPHEADER *pkzip = (PKZIPHEADER *) in;
-
-    /* Return compressed file name */
-    int len = FLIP16(pkzip->filenameLength);
-    if (len >= MAXPATHLEN) len = MAXPATHLEN - 1;
-    fread(filename, len, 1, fd);
-    filename[len] = 0;
-  }
-
-  fclose(fd);
-}
-
-int load_archive(char *filename, unsigned char *buffer, int maxsize)
 {
   int size = 0;
   char in[CHUNKSIZE];
@@ -132,7 +102,7 @@ int load_archive(char *filename, unsigned char *buffer, int maxsize)
   /* Mega CD BIOS are required files */
   if (!strcmp(filename,CD_BIOS_US) || !strcmp(filename,CD_BIOS_EU) || !strcmp(filename,CD_BIOS_JP)) 
   {
-    sprintf(msg,"Unable to open CD BIOS");
+    sprintf(msg,"Unable to open %s", filename + 14);
   }
 
   if (!fd)
@@ -187,19 +157,23 @@ int load_archive(char *filename, unsigned char *buffer, int maxsize)
       return 0;
     }
 
+    /* Compressed filename offset */
+    int offset = sizeof (PKZIPHEADER) + FLIP16(pkzip->filenameLength);
+ 
+    if (extension)
+    {
+      memcpy(extension, &in[offset - 3], 3);
+      extension[3] = 0;
+    }
+
+   
     /* Initial Zip buffer offset */
-    int offset = sizeof (PKZIPHEADER) + FLIP16(pkzip->filenameLength) + FLIP16(pkzip->extraDataLength);
+    offset += FLIP16(pkzip->extraDataLength);
     zs.next_in = (Bytef *)&in[offset];
 
     /* Initial Zip remaining chunk size */
     zs.avail_in = CHUNKSIZE - offset;
 
-    /* Overwrite input filename with compressed filename */
-    offset = FLIP16(pkzip->filenameLength);
-    if (offset >= MAXPATHLEN) offset = MAXPATHLEN - 1;
-    strncpy(filename, &in[sizeof(PKZIPHEADER)], offset);
-    filename[offset] = 0;
-
     /* Start unzipping file */
     do
     {
@@ -255,6 +229,13 @@ int load_archive(char *filename, unsigned char *buffer, int maxsize)
     sprintf((char *)msg,"Loading %d bytes ...", size);
     GUI_MsgBoxOpen("Information", (char *)msg, 1);
 
+    /* filename extension */
+    if (extension)
+    {
+      memcpy(extension, &filename[strlen(filename) - 3], 3);
+      extension[3] = 0;
+    }
+
     /* Read into buffer */
     int left = size;
     while (left > CHUNKSIZE)

source/gx/fileio/fileio.h

@@ -42,6 +42,6 @@
 #define _FILEIO_H_
 
 /* Function prototypes */
-int load_archive(char *filename, unsigned char *buffer, int maxsize);
+int load_archive(char *filename, unsigned char *buffer, int maxsize, char *extension);
 
 #endif /* _FILEIO_H_ */

source/gx/main.c

@@ -118,7 +118,7 @@ static void init_machine(void)
     fclose(fp);
 
     /* check BOOT ROM */
-    if (!strncmp((char *)(boot_rom + 0x120),"GENESIS OS", 10))
+    if (!memcmp((char *)(boot_rom + 0x120),"GENESIS OS", 10))
     {
       /* mark Genesis BIOS as loaded */
       system_bios = SYSTEM_MD;

source/loadrom.c

@@ -403,13 +403,13 @@ int load_bios(void)
         switch (region_code)
         {
           case REGION_USA:
-            size = load_archive(CD_BIOS_US, scd.bootrom, sizeof(scd.bootrom));
+            size = load_archive(CD_BIOS_US, scd.bootrom, sizeof(scd.bootrom), 0);
             break;
           case REGION_EUROPE:
-            size = load_archive(CD_BIOS_EU, scd.bootrom, sizeof(scd.bootrom));
+            size = load_archive(CD_BIOS_EU, scd.bootrom, sizeof(scd.bootrom), 0);
             break;
           default:
-            size = load_archive(CD_BIOS_JP, scd.bootrom, sizeof(scd.bootrom));
+            size = load_archive(CD_BIOS_JP, scd.bootrom, sizeof(scd.bootrom), 0);
             break;
         }
 
@@ -458,7 +458,7 @@ int load_bios(void)
         if (cart.romsize <= 0x400000)
         {
           /* load Game Gear "BIOS" file */
-          size = load_archive(GG_BIOS, cart.rom + 0x400000, 0x100000);
+          size = load_archive(GG_BIOS, cart.rom + 0x400000, 0x100000, 0);
 
           if (size > 0)
           {
@@ -489,13 +489,13 @@ int load_bios(void)
           switch (region_code)
           {
             case REGION_USA:
-              size = load_archive(MS_BIOS_US, cart.rom + 0x400000, 0x100000);
+              size = load_archive(MS_BIOS_US, cart.rom + 0x400000, 0x100000, 0);
               break;
             case REGION_EUROPE:
-              size = load_archive(MS_BIOS_EU, cart.rom + 0x400000, 0x100000);
+              size = load_archive(MS_BIOS_EU, cart.rom + 0x400000, 0x100000, 0);
               break;
             default:
-              size = load_archive(MS_BIOS_JP, cart.rom + 0x400000, 0x100000);
+              size = load_archive(MS_BIOS_JP, cart.rom + 0x400000, 0x100000, 0);
               break;
           }
 
@@ -548,9 +548,13 @@ int load_rom(char *filename)
   {
     cdd_unload();
   }
+  else
+  {
+    cdd.loaded = 0;
+  }
 
   /* .cue file support */
-  if (!strncmp(".cue", &filename[strlen(filename) - 4], 4))
+  if (!memcmp(".cue", &filename[strlen(filename) - 4], 4))
   {
     /* open associated .bin file */
     strncpy(&filename[strlen(filename) - 4], ".bin", 4);
@@ -565,7 +569,7 @@ int load_rom(char *filename)
   }
 
   /* auto-detect CD image file */
-  if (!strncmp("SEGADISCSYSTEM", buf + 0x10, 14))
+  if (!memcmp("SEGADISCSYSTEM", buf + 0x10, 14))
   {
     /* file header pointer (BIN format) */
     header = buf + 0x10;
@@ -573,7 +577,7 @@ int load_rom(char *filename)
     /* enable CD hardware */
     system_hw = SYSTEM_MCD;
   }
-  else if (!strncmp("SEGADISCSYSTEM", buf, 14))
+  else if (!memcmp("SEGADISCSYSTEM", buf, 14))
   {    
     /* file header pointer (ISO format) */
     header = buf;
@@ -583,25 +587,29 @@ int load_rom(char *filename)
   }
   else
   {
-    /* load file into ROM buffer (input filename is overwritten by uncompressed filename) */
+    /* load file into ROM buffer */
-    int size = load_archive(filename, cart.rom, sizeof(cart.rom));
+    char extension[4];
+    int size = load_archive(filename, cart.rom, sizeof(cart.rom), extension);
     if (!size) return(0);
 
     /* mark CD BIOS as unloaded */
     system_bios &= ~0x10;
 
+    /* convert lower case to upper case */
+    *(uint32 *)(extension) &= 0xdfdfdfdf;
+
     /* Auto-detect system hardware from ROM file extension */
-    if (!strncmp(".sms", &filename[strlen(filename) - 4], 4))
+    if (!memcmp("SMS", &extension[0], 3))
     {
       /* Master System II hardware */
       system_hw = SYSTEM_SMS2;
     }
-    else if (!strncmp(".gg", &filename[strlen(filename) - 3], 3))
+    else if (!memcmp("GG", &extension[1], 2))
     {
       /* Game Gear hardware (GG mode) */
       system_hw = SYSTEM_GG;
     }
-    else if (!strncmp(".sg", &filename[strlen(filename) - 3], 3))
+    else if (!memcmp("SG", &extension[1], 2))
     {
       /* SG-1000 hardware */
       system_hw = SYSTEM_SG;
@@ -612,7 +620,7 @@ int load_rom(char *filename)
       system_hw = SYSTEM_MD;
 
       /* Decode .MDX format */
-      if (!strncmp(".mdx", &filename[strlen(filename) - 4], 4))
+      if (!memcmp("MDX", &extension[0], 3))
       {
         for (i = 4; i < size - 1; i++)
         {
@@ -623,7 +631,7 @@ int load_rom(char *filename)
     }
 
     /* auto-detect 512 byte extra header */
-    if (strncmp((char *)(cart.rom + 0x100),"SEGA", 4) && ((size / 512) & 1))
+    if (memcmp((char *)(cart.rom + 0x100), "SEGA", 4) && ((size / 512) & 1))
     {
       /* remove header */
       size -= 512;
@@ -817,12 +825,12 @@ void get_region(char *romheader)
       int country = 0;
 
       /* from Gens */
-      if (!strncmp(rominfo.country, "eur", 3)) country |= 8;
+      if (!memcmp(rominfo.country, "eur", 3)) country |= 8;
-      else if (!strncmp(rominfo.country, "EUR", 3)) country |= 8;
+      else if (!memcmp(rominfo.country, "EUR", 3)) country |= 8;
-      else if (!strncmp(rominfo.country, "jap", 3)) country |= 1;
+      else if (!memcmp(rominfo.country, "jap", 3)) country |= 1;
-      else if (!strncmp(rominfo.country, "JAP", 3)) country |= 1;
+      else if (!memcmp(rominfo.country, "JAP", 3)) country |= 1;
-      else if (!strncmp(rominfo.country, "usa", 3)) country |= 4;
+      else if (!memcmp(rominfo.country, "usa", 3)) country |= 4;
-      else if (!strncmp(rominfo.country, "USA", 3)) country |= 4;
+      else if (!memcmp(rominfo.country, "USA", 3)) country |= 4;
       else
       {
         int i;

source/state.c

@@ -46,7 +46,7 @@ int state_load(unsigned char *state)
   char version[17];
   load_param(version,16);
   version[16] = 0;
-  if (strncmp(version,STATE_VERSION,11))
+  if (memcmp(version,STATE_VERSION,11))
   {
     return -1;
   }

source/win/fileio.c

@@ -45,9 +45,8 @@
 #include <zlib.h>
 
 static int check_zip(char *filename);
-static int gzsize(gzFile *gd);
 
-int load_archive(char *filename, unsigned char *buffer, int maxsize)
+int load_archive(char *filename, unsigned char *buffer, int maxsize, char *extension)
 {
   int size = 0;
   
@@ -55,6 +54,7 @@ int load_archive(char *filename, unsigned char *buffer, int maxsize)
   {
     unz_file_info info;
     int ret = 0;
+    char fname[256];
 
     /* Attempt to open the archive */
     unzFile *fd = unzOpen(filename);
@@ -69,13 +69,20 @@ int load_archive(char *filename, unsigned char *buffer, int maxsize)
     }
 
     /* Get file informations and update filename */
-    ret = unzGetCurrentFileInfo(fd, &info, filename, 128, NULL, 0, NULL, 0);
+    ret = unzGetCurrentFileInfo(fd, &info, fname, 256, NULL, 0, NULL, 0);
     if(ret != UNZ_OK)
     {
       unzClose(fd);
       return 0;
     }
 
+    /* Compressed filename extension */
+    if (extension)
+    {
+      strncpy(extension, &fname[strlen(fname) - 3], 3);
+      extension[3] = 0;
+    }
+
     /* Open the file for reading */
     ret = unzOpenCurrentFile(fd);
     if(ret != UNZ_OK)
@@ -121,6 +128,13 @@ int load_archive(char *filename, unsigned char *buffer, int maxsize)
     /* Read file data */
     size = gzread(gd, buffer, maxsize);
 
+    /* filename extension */
+    if (extension)
+    {
+      strncpy(extension, &filename[strlen(filename) - 3], 3);
+      extension[3] = 0;
+    }
+
     /* Close file */
     gzclose(gd);
   }
@@ -143,25 +157,3 @@ static int check_zip(char *filename)
   if(memcmp(buf, "PK", 2) == 0) return (1);
   return (0);
 }
-
-
-/*
-    Returns the size of a GZ compressed file.
-*/
-static int gzsize(gzFile *gd)
-{
-  #define CHUNKSIZE   (0x10000)
-  int size = 0, length = 0;
-  unsigned char buffer[CHUNKSIZE];
-  gzrewind(gd);
-  do
-  {
-    size = gzread(gd, buffer, CHUNKSIZE);
-    if(size <= 0) break;
-    length += size;
-  }
-  while (!gzeof(gd));
-  gzrewind(gd);
-  return (length);
-  #undef CHUNKSIZE
-}

source/win/fileio.h

@@ -43,6 +43,6 @@
 #define _FILEIO_H_
 
 /* Function prototypes */
-extern int load_archive(char *filename, unsigned char *buffer, int maxsize);
+extern int load_archive(char *filename, unsigned char *buffer, int maxsize, char *extension);
 
 #endif /* _FILEIO_H_ */

source/win/main.c

@@ -701,7 +701,7 @@ int main (int argc, char **argv)
     fclose(fp);
 
     /* check BOOT ROM */
-    if (!strncmp((char *)(boot_rom + 0x120),"GENESIS OS", 10))
+    if (!memcmp((char *)(boot_rom + 0x120),"GENESIS OS", 10))
     {
       /* mark Genesis BIOS as loaded */
       system_bios = SYSTEM_MD;