From 9a40616f907abb2b4262970e44818630fb2d115a Mon Sep 17 00:00:00 2001
From: "Ryan C. Gordon" <icculus@icculus.org>
Date: Tue, 13 Feb 2007 10:09:17 +0000
Subject: [PATCH] SDL_image shouldn't dereference a rwops if it's NULL.

  Fixes Bugzilla #284.
---
 IMG_bmp.c | 2 ++
 IMG_gif.c | 2 ++
 IMG_jpg.c | 2 ++
 IMG_lbm.c | 2 ++
 IMG_pcx.c | 2 ++
 IMG_png.c | 2 ++
 IMG_pnm.c | 2 ++
 IMG_tif.c | 2 ++
 IMG_xcf.c | 2 ++
 IMG_xpm.c | 8 ++++++--
 IMG_xv.c  | 2 ++
 IMG_xxx.c | 2 ++
 12 files changed, 28 insertions(+), 2 deletions(-)

diff --git a/IMG_bmp.c b/IMG_bmp.c
index 002e9809..b7bf9684 100644
--- a/IMG_bmp.c
+++ b/IMG_bmp.c
@@ -36,6 +36,8 @@ int IMG_isBMP(SDL_RWops *src)
 	int is_BMP;
 	char magic[2];
 
+	if ( !src )
+		return 0;
 	start = SDL_RWtell(src);
 	is_BMP = 0;
 	if ( SDL_RWread(src, magic, sizeof(magic), 1) ) {
diff --git a/IMG_gif.c b/IMG_gif.c
index be97d672..ef0ce0e1 100644
--- a/IMG_gif.c
+++ b/IMG_gif.c
@@ -36,6 +36,8 @@ int IMG_isGIF(SDL_RWops *src)
 	int is_GIF;
 	char magic[6];
 
+	if ( !src )
+		return 0;
 	start = SDL_RWtell(src);
 	is_GIF = 0;
 	if ( SDL_RWread(src, magic, sizeof(magic), 1) ) {
diff --git a/IMG_jpg.c b/IMG_jpg.c
index 2cbd592a..fb0c6cda 100644
--- a/IMG_jpg.c
+++ b/IMG_jpg.c
@@ -179,6 +179,8 @@ int IMG_isJPG(SDL_RWops *src)
 	/* Blame me, not Sam, if this doesn't work right. */
 	/* And don't forget to report the problem to the the sdl list too! */
 
+	if ( !src )
+		return 0;
 	start = SDL_RWtell(src);
 	is_JPG = 0;
 	in_scan = 0;
diff --git a/IMG_lbm.c b/IMG_lbm.c
index c32ba1cb..f52724e6 100644
--- a/IMG_lbm.c
+++ b/IMG_lbm.c
@@ -65,6 +65,8 @@ int IMG_isLBM( SDL_RWops *src )
 	int   is_LBM;
 	Uint8 magic[4+4+4];
 
+	if ( !src ) 
+		return 0;
 	start = SDL_RWtell(src);
 	is_LBM = 0;
 	if ( SDL_RWread( src, magic, sizeof(magic), 1 ) )
diff --git a/IMG_pcx.c b/IMG_pcx.c
index ed97315b..231e2af2 100644
--- a/IMG_pcx.c
+++ b/IMG_pcx.c
@@ -69,6 +69,8 @@ int IMG_isPCX(SDL_RWops *src)
 	const int PCX_RunLength_Encoding = 1;
 	struct PCXheader pcxh;
 
+	if ( !src )
+		return 0;
 	start = SDL_RWtell(src);
 	is_PCX = 0;
 	if ( SDL_RWread(src, &pcxh, sizeof(pcxh), 1) == 1 ) {
diff --git a/IMG_png.c b/IMG_png.c
index a5c04fee..8ab2004d 100644
--- a/IMG_png.c
+++ b/IMG_png.c
@@ -273,6 +273,8 @@ int IMG_isPNG(SDL_RWops *src)
 	if ( IMG_InitPNG() < 0 ) {
 		return 0;
 	}
+	if ( !src )
+		return 0;
 	start = SDL_RWtell(src);
 	is_PNG = 0;
 	if ( SDL_RWread(src, buf, 1, PNG_BYTES_TO_CHECK) == PNG_BYTES_TO_CHECK ) {
diff --git a/IMG_pnm.c b/IMG_pnm.c
index 72375ebf..958bd960 100644
--- a/IMG_pnm.c
+++ b/IMG_pnm.c
@@ -44,6 +44,8 @@ int IMG_isPNM(SDL_RWops *src)
 	int is_PNM;
 	char magic[2];
 
+	if ( !src )
+		return 0;
 	start = SDL_RWtell(src);
 	is_PNM = 0;
 	if ( SDL_RWread(src, magic, sizeof(magic), 1) ) {
diff --git a/IMG_tif.c b/IMG_tif.c
index 1d5102c5..6cf726ef 100644
--- a/IMG_tif.c
+++ b/IMG_tif.c
@@ -174,6 +174,8 @@ int IMG_isTIF(SDL_RWops* src)
 	if ( IMG_InitTIF() < 0 ) {
 		return 0;
 	}
+	if ( !src )
+		return 0;
 	start = SDL_RWtell(src);
 	is_TIF = 0;
 
diff --git a/IMG_xcf.c b/IMG_xcf.c
index d32a0bf5..37927ded 100644
--- a/IMG_xcf.c
+++ b/IMG_xcf.c
@@ -213,6 +213,8 @@ int IMG_isXCF(SDL_RWops *src)
 	int is_XCF;
 	char magic[14];
 
+	if ( !src )
+		return 0;
 	start = SDL_RWtell(src);
 	is_XCF = 0;
 	if ( SDL_RWread(src, magic, sizeof(magic), 1) ) {
diff --git a/IMG_xpm.c b/IMG_xpm.c
index 87529790..fdd04dd2 100644
--- a/IMG_xpm.c
+++ b/IMG_xpm.c
@@ -59,6 +59,8 @@ int IMG_isXPM(SDL_RWops *src)
 	int is_XPM;
 	char magic[9];
 
+	if ( !src )
+		return 0;
 	start = SDL_RWtell(src);
 	is_XPM = 0;
 	if ( SDL_RWread(src, magic, sizeof(magic), 1) ) {
@@ -326,7 +328,8 @@ static SDL_Surface *load_xpm(char **xpm, SDL_RWops *src)
 	linebuf = NULL;
 	buflen = 0;
 
-	start = SDL_RWtell(src);
+	if ( src ) 
+		start = SDL_RWtell(src);
 
 	if(xpm)
 		xpmlines = &xpm;
@@ -453,7 +456,8 @@ static SDL_Surface *load_xpm(char **xpm, SDL_RWops *src)
 
 done:
 	if(error) {
-		SDL_RWseek(src, start, SEEK_SET);
+		if ( src )
+			SDL_RWseek(src, start, SEEK_SET);
 		if ( image ) {
 			SDL_FreeSurface(image);
 			image = NULL;
diff --git a/IMG_xv.c b/IMG_xv.c
index 2d15cb13..e685f5b7 100644
--- a/IMG_xv.c
+++ b/IMG_xv.c
@@ -89,6 +89,8 @@ int IMG_isXV(SDL_RWops *src)
 	int is_XV;
 	int w, h;
 
+	if ( !src )
+		return 0;
 	start = SDL_RWtell(src);
 	is_XV = 0;
 	if ( get_header(src, &w, &h) == 0 ) {
diff --git a/IMG_xxx.c b/IMG_xxx.c
index 524af494..9a014d6e 100644
--- a/IMG_xxx.c
+++ b/IMG_xxx.c
@@ -34,6 +34,8 @@ int IMG_isXXX(SDL_RWops *src)
 	int start;
 	int is_XXX;
 
+	if ( !src )
+		return 0;
 	start = SDL_RWtell(src);
 	is_XXX = 0;