engine: imagelib: fix integer overflow on huge images when calculating reflectivity

engine/common/imagelib/img_bmp.c

@@ -28,7 +28,7 @@ qboolean Image_LoadBMP( const char *name, const byte *buffer, fs_offset_t filesi
 	rgba_t	palette[256] = { 0 };
 	int	i, columns, column, rows, row, bpp = 1;
 	int	cbPalBytes = 0, padSize = 0, bps = 0;
-	int	reflectivity[3] = { 0, 0, 0 };
+	uint	reflectivity[3] = { 0, 0, 0 };
 	qboolean	load_qfont = false;
 	bmp_t	bhdr;
 	fs_offset_t estimatedSize;

engine/common/imagelib/img_tga.c

@@ -29,7 +29,7 @@ qboolean Image_LoadTGA( const char *name, const byte *buffer, fs_offset_t filesi
 	rgba_t	palette[256];
 	byte	red = 0, green = 0, blue = 0, alpha = 0;
 	int	readpixelcount, pixelcount;
-	int	reflectivity[3] = { 0, 0, 0 };
+	uint	reflectivity[3] = { 0, 0, 0 };
 	qboolean	compressed;
 	tga_t	targa_header;
 

engine/common/imagelib/img_wad.c

@@ -360,7 +360,7 @@ qboolean Image_LoadMIP( const char *name, const byte *buffer, fs_offset_t filesi
 	byte	*fin, *pal;
 	int	ofs[4], rendermode;
 	int	i, pixels, numcolors;
-	int	reflectivity[3] = { 0, 0, 0 };
+	uint	reflectivity[3] = { 0, 0, 0 };
 
 	if( filesize < sizeof( mip ))
 		return false;