fix -Wsign-compare

src/gd_io.c

@@ -109,7 +109,7 @@ int gdGetWord(int *result, gdIOCtx *ctx)
 
 int gdGetWordLSB(signed short int *result, gdIOCtx *ctx)
 {
-	unsigned int high = 0, low = 0;
+	int high = 0, low = 0;
 	low = (ctx->getC) (ctx);
 	if (low == EOF) {
  		return 0;

src/gd_jpeg.c

@@ -302,7 +302,8 @@ BGD_DECLARE(gdImagePtr) gdImageCreateFromJpegCtx(gdIOCtx *infile)
 	volatile JSAMPROW row = 0;
 	volatile gdImagePtr im = 0;
 	JSAMPROW rowptr[1];
-	int i, j, retval;
+	JDIMENSION i, j;
+	int retval;
 	JDIMENSION nrows;
 	int channels = 3;
 	int inverted = 0;
@@ -919,7 +920,7 @@ safeboolean empty_output_buffer(j_compress_ptr cinfo)
 void term_destination(j_compress_ptr cinfo)
 {
 	my_dest_ptr dest = (my_dest_ptr) cinfo->dest;
-	size_t datacount = OUTPUT_BUF_SIZE - dest->pub.free_in_buffer;
+	int datacount = OUTPUT_BUF_SIZE - dest->pub.free_in_buffer;
 
 	/* Write any data remaining in the buffer */
 	if(datacount > 0) {

src/gd_png.c

@@ -81,7 +81,7 @@ gdPngReadData (png_structp png_ptr, png_bytep data, png_size_t length)
 {
 	int check;
 	check = gdGetBuf (data, length, (gdIOCtx *) png_get_io_ptr (png_ptr));
-	if (check != length) {
+	if (check != (int)length) {
 		png_error(png_ptr, "Read Error: truncated data");
 	}
 }

src/gd_tiff.c

@@ -170,7 +170,7 @@ static toff_t tiff_seekproc(thandle_t clientdata, toff_t offset, int from)
 		th->pos = offset;
 	}
 
-	return result ? offset : -1;
+	return result ? offset : (toff_t)-1;
 }
 
 /* TIFFCloseProc tiff_closeproc - used to finally close the TIFF file */
@@ -253,7 +253,7 @@ BGD_DECLARE(void) tiffWriter(gdImagePtr image, gdIOCtx *out, int bitDepth)
 	gdImageSetClip(image, 0, 0, width, height);
 
 	/* handle old-style single-colour mapping to 100% transparency */
-	if(image->transparent != 0xffffffff) {
+	if(image->transparent != -1) {
 		/* set our 100% transparent colour value */
 		transparentColorR = gdImageRed(image, image->transparent);
 		transparentColorG = gdImageGreen(image, image->transparent);
@@ -310,7 +310,7 @@ BGD_DECLARE(void) tiffWriter(gdImagePtr image, gdIOCtx *out, int bitDepth)
 
 	/* here, we check if the 'save alpha' flag is set on the source gd image */
 	if(	(bitDepth == 24) &&
-		(image->saveAlphaFlag || image->transparent != 0xffffffff)) {
+		(image->saveAlphaFlag || image->transparent != -1)) {
 		/* so, we need to store the alpha values too! 
 		 * Also, tell TIFF what the extra sample means (associated alpha) */
 		samplesPerPixel = 4;
@@ -357,7 +357,7 @@ BGD_DECLARE(void) tiffWriter(gdImagePtr image, gdIOCtx *out, int bitDepth)
 				scan[(x * samplesPerPixel) + 0] = color;
 			} else {
 				/* write out 24 bit value in 3 (or 4 if transparent) bytes */
-				if(image->saveAlphaFlag || image->transparent != 0xffffffff) {
+				if(image->saveAlphaFlag || image->transparent != -1) {
 					scan[(x * samplesPerPixel) + 3] = a;
 				}
 
@@ -662,8 +662,7 @@ static int createFromTiffLines(TIFF *tif, gdImagePtr im, uint16 bps, uint16 phot
 		char has_alpha, char is_bw, int extra)
 {
 	uint16  planar;
-	uint32 im_height, im_width;
-	int y;
+	uint32 im_height, im_width, y;
 
 	unsigned char *buffer;
 

src/gdft.c

@@ -1528,7 +1528,7 @@ static FcPattern* find_font(FcPattern* pattern)
 static char* find_postscript_font(FcPattern **fontpattern, char* fontname)
 {
   FcPattern* font = NULL;
-  int i;
+  size_t i;
 
   *fontpattern = NULL;
   for (i = 0; i < sizeof(postscript_alias)/sizeof(*postscript_alias); i++) {