i'm sure there are plenty of bugs here for you guys to fix

[xonotic/darkplaces.git] / image_png.c

diff --git a/image_png.c b/image_png.c
index d9d7a5004f844dfe13aacdfc444493507b56e6d4..6cf182a1e94a958f2491754940c60d1bed702ecc 100644 (file)
--- a/image_png.c
+++ b/image_png.c
@@ -50,7 +50,7 @@ static unsigned int           (*qpng_get_valid)                       (void*, void*, unsigned int);
 static unsigned int            (*qpng_get_rowbytes)            (void*, void*);
 static unsigned char   (*qpng_get_channels)            (void*, void*);
 static unsigned char   (*qpng_get_bit_depth)           (void*, void*);
-static unsigned int            (*qpng_get_IHDR)                        (void*, void*, unsigned int*, unsigned int*, int *, int *, int *, int *, int *);
+static unsigned int            (*qpng_get_IHDR)                        (void*, void*, unsigned long*, unsigned long*, int *, int *, int *, int *, int *);
 static char*                   (*qpng_get_libpng_ver)          (void*);
 
 static dllfunction_t pngfuncs[] =
@@ -189,8 +189,8 @@ static struct
        int             BitDepth;
        int             BytesPerPixel;
        int             ColorType;
-       unsigned int    Height;
-       unsigned int    Width;
+       unsigned long   Height; // retarded libpng 1.2 pngconf.h uses long (64bit/32bit depending on arch)
+       unsigned long   Width; // retarded libpng 1.2 pngconf.h uses long (64bit/32bit depending on arch)
        int             Interlace;
        int             Compression;
        int             Filter;
@@ -233,7 +233,7 @@ unsigned char *PNG_LoadImage (const unsigned char *raw, int filesize, int matchw
 {
        unsigned int    y;
        void *png, *pnginfo;
-       unsigned char *imagedata;
+       unsigned char *imagedata = NULL;
        unsigned char ioBuffer[8192];
 
        // FIXME: register an error handler so that abort() won't be called on error
@@ -248,6 +248,10 @@ unsigned char *PNG_LoadImage (const unsigned char *raw, int filesize, int matchw
        if(!png)
                return NULL;
 
+       // this must be memset before the setjmp error handler, because it relies
+       // on the fields in this struct for cleanup
+       memset(&my_png, 0, sizeof(my_png));
+
        // NOTE: this relies on jmp_buf being the first thing in the png structure
        // created by libpng! (this is correct for libpng 1.2.x)
 #ifdef __cplusplus
@@ -260,6 +264,12 @@ unsigned char *PNG_LoadImage (const unsigned char *raw, int filesize, int matchw
        if (setjmp(png))
 #endif
        {
+               if (my_png.Data)
+                       Mem_Free(my_png.Data);
+               my_png.Data = NULL;
+               if (my_png.FRowPtrs)
+                       Mem_Free(my_png.FRowPtrs);
+               my_png.FRowPtrs = NULL;
                qpng_destroy_read_struct(&png, &pnginfo, 0);
                return NULL;
        }
@@ -273,7 +283,6 @@ unsigned char *PNG_LoadImage (const unsigned char *raw, int filesize, int matchw
        }
        qpng_set_sig_bytes(png, 0);
 
-       memset(&my_png, 0, sizeof(my_png));
        my_png.tmpBuf = raw;
        my_png.tmpBuflength = filesize;
        my_png.tmpi = 0;
@@ -288,7 +297,21 @@ unsigned char *PNG_LoadImage (const unsigned char *raw, int filesize, int matchw
        qpng_set_read_fn(png, ioBuffer, (void *)PNG_fReadData);
        qpng_read_info(png, pnginfo);
        qpng_get_IHDR(png, pnginfo, &my_png.Width, &my_png.Height,&my_png.BitDepth, &my_png.ColorType, &my_png.Interlace, &my_png.Compression, &my_png.Filter);
-       if ((matchwidth && my_png.Width != (unsigned int)matchwidth) || (matchheight && my_png.Height != (unsigned int)matchheight))
+
+       // this check guards against pngconf.h with unsigned int *width/height parameters on big endian systems by detecting the strange values and shifting them down 32bits
+       // (if it's little endian the unwritten bytes are the most significant
+       //  ones and we don't worry about that)
+       //
+       // this is only necessary because of retarded 64bit png_uint_32 types in libpng 1.2, which can (conceivably) vary by platform
+#if LONG_MAX > 4000000000
+       if (my_png.Width > LONG_MAX || my_png.Height > LONG_MAX)
+       {
+               my_png.Width >>= 32;
+               my_png.Height >>= 32;
+       }
+#endif
+
+       if ((matchwidth && my_png.Width != (unsigned long)matchwidth) || (matchheight && my_png.Height != (unsigned long)matchheight))
        {
                qpng_destroy_read_struct(&png, &pnginfo, 0);
                return NULL;
@@ -319,9 +342,10 @@ unsigned char *PNG_LoadImage (const unsigned char *raw, int filesize, int matchw
        my_png.FRowPtrs = (unsigned char **)Mem_Alloc(tempmempool, my_png.Height * sizeof(*my_png.FRowPtrs));
        if (my_png.FRowPtrs)
        {
-               my_png.Data = (unsigned char *)Mem_Alloc(tempmempool, my_png.Height * my_png.FRowBytes);
-               if(my_png.Data)
+               imagedata = (unsigned char *)Mem_Alloc(tempmempool, my_png.Height * my_png.FRowBytes);
+               if(imagedata)
                {
+                       my_png.Data = imagedata;
                        for(y = 0;y < my_png.Height;y++)
                                my_png.FRowPtrs[y] = my_png.Data + y * my_png.FRowBytes;
                        qpng_read_image(png, my_png.FRowPtrs);
@@ -329,6 +353,7 @@ unsigned char *PNG_LoadImage (const unsigned char *raw, int filesize, int matchw
                else
                        Con_DPrintf("PNG_LoadImage : not enough memory\n");
                Mem_Free(my_png.FRowPtrs);
+               my_png.FRowPtrs = NULL;
        }
        else
                Con_DPrintf("PNG_LoadImage : not enough memory\n");
@@ -336,9 +361,8 @@ unsigned char *PNG_LoadImage (const unsigned char *raw, int filesize, int matchw
        qpng_read_end(png, pnginfo);
        qpng_destroy_read_struct(&png, &pnginfo, 0);
 
-       image_width = my_png.Width;
-       image_height = my_png.Height;
-       imagedata = my_png.Data;
+       image_width = (int)my_png.Width;
+       image_height = (int)my_png.Height;
 
        if (my_png.BitDepth != 8)
        {