Remove dead code

`_php_image_output()` is only ever called for `PHP_GDIMG_CONVERT_WBM`,
`PHP_GDIMG_TYPE_GD` and `PHP_GDIMG_TYPE_GD2`.  All other image types
solely use the more flexible `_php_image_output_ctx()`.

Author: cmb69

ext/gd/gd.c

@@ -2595,7 +2595,6 @@ static void _php_image_output(INTERNAL_FUNCTION_PARAMETERS, int image_type, char
 	int q = -1, i, t = 1;
 
 	/* The quality parameter for Wbmp stands for the foreground when called from image2wbmp() */
-	/* When called from imagewbmp() the quality parameter stands for the foreground color. Default: black. */
 	/* The quality parameter for gd2 stands for chunk size */
 
 	if (zend_parse_parameters(argc, "r|pll", &imgind, &file, &file_len, &quality, &type) == FAILURE) {
@@ -2635,15 +2634,6 @@ static void _php_image_output(INTERNAL_FUNCTION_PARAMETERS, int image_type, char
 				}
 				gdImageWBMP(im, q, fp);
 				break;
-			case PHP_GDIMG_TYPE_JPG:
-				(*func_p)(im, fp, q);
-				break;
-			case PHP_GDIMG_TYPE_WBM:
-				for (i = 0; i < gdImageColorsTotal(im); i++) {
-					if (gdImageRed(im, i) == 0) break;
-				}
-				(*func_p)(im, i, fp);
-				break;
 			case PHP_GDIMG_TYPE_GD:
 				(*func_p)(im, fp);
 				break;
@@ -2654,11 +2644,7 @@ static void _php_image_output(INTERNAL_FUNCTION_PARAMETERS, int image_type, char
 				(*func_p)(im, fp, q, t);
 				break;
 			default:
-				if (q == -1) {
-					q = 128;
-				}
-				(*func_p)(im, fp, q, t);
-				break;
+				ZEND_ASSERT(0);
 		}
 		fflush(fp);
 		fclose(fp);
@@ -2684,17 +2670,6 @@ static void _php_image_output(INTERNAL_FUNCTION_PARAMETERS, int image_type, char
   				}
 				gdImageWBMP(im, q, tmp);
 				break;
-			case PHP_GDIMG_TYPE_JPG:
-				(*func_p)(im, tmp, q);
-				break;
-			case PHP_GDIMG_TYPE_WBM:
-				for (i = 0; i < gdImageColorsTotal(im); i++) {
-					if (gdImageRed(im, i) == 0) {
-						break;
-					}
-				}
-				(*func_p)(im, q, tmp);
-				break;
 			case PHP_GDIMG_TYPE_GD:
 				(*func_p)(im, tmp);
 				break;
@@ -2705,8 +2680,7 @@ static void _php_image_output(INTERNAL_FUNCTION_PARAMETERS, int image_type, char
 				(*func_p)(im, tmp, q, t);
 				break;
 			default:
-				(*func_p)(im, tmp);
-				break;
+				ZEND_ASSERT(0);
 		}
 
 		fseek(tmp, 0, SEEK_SET);

ext/gd/gd_ctx.c

@@ -93,9 +93,8 @@ static void _php_image_output_ctx(INTERNAL_FUNCTION_PARAMETERS, int image_type,
 	php_stream *stream;
 	int close_stream = 1;
 
-	/* The third (quality) parameter for Wbmp stands for the foreground when called from image2wbmp().
-	 * The third (quality) parameter for Wbmp and Xbm stands for the foreground color index when called
-	 * from imagey<type>().
+	/* The third (quality) parameter for Wbmp and Xbm stands for the foreground color index when called
+	 * from image<type>().
 	 */
 	switch (image_type) {
 		case PHP_GDIMG_TYPE_XBM:
@@ -177,10 +176,6 @@ static void _php_image_output_ctx(INTERNAL_FUNCTION_PARAMETERS, int image_type,
 	}
 
 	switch(image_type) {
-		case PHP_GDIMG_CONVERT_WBM:
-			if(q<0||q>255) {
-				php_error_docref(NULL, E_WARNING, "Invalid threshold value '%d'. It must be between 0 and 255", q);
-			}
 		case PHP_GDIMG_TYPE_JPG:
 			(*func_p)(im, ctx, q);
 			break;