Fixed #60160 and added a test for it

Author: winks

ext/gd/libgd/gd.c

@@ -1894,19 +1894,14 @@ void gdImageFill(gdImagePtr im, int x, int y, int nc)
 	if (im->sx < 4) {
 		int ix = x, iy = y, c;
 		do {
-			c = gdImageGetPixel(im, ix, iy);
-			if (c != oc) {
-				goto done;
-			}
-			gdImageSetPixel(im, ix, iy, nc);
-		} while(ix++ < (im->sx -1));
-		ix = x; iy = y + 1;
-		do {
-			c = gdImageGetPixel(im, ix, iy);
-			if (c != oc) {
-				goto done;
-			}
-			gdImageSetPixel(im, ix, iy, nc);
+			do {
+				c = gdImageGetPixel(im, ix, iy);
+				if (c != oc) {
+					goto done;
+				}
+				gdImageSetPixel(im, ix, iy, nc);
+			} while(ix++ < (im->sx -1));
+			ix = x;
 		} while(iy++ < (im->sy -1));
 		goto done;
 	}

ext/gd/tests/bug60160.phpt

@@ -0,0 +1,26 @@
+--TEST--
+Bug #60160 (imagefill does not work correctly for small images) @see bug51671
+--SKIPIF--
+<?php
+	if(!extension_loaded('gd')){ die('skip gd extension not available'); }
+?>
+--FILE--
+<?php
+$w = 3;
+$h = 50;
+$im = imagecreatetruecolor($w, $h);
+$white = imagecolorallocate($im, 255, 255, 255);
+imagefill($im, 0, 0, $white);
+
+for ($ix = 0; $ix < $w; $ix++) {
+        for ($iy = 0; $iy < $h; $iy++) {
+                if (($c = imagecolorat($im, $ix, $iy)) != $white) {
+                        printf("Failed, ($ix, $iy) is %X\n", $c);
+                }
+        }
+}
+
+echo "OK\n";
+?>
+--EXPECTF--
+OK