Fix phpGH-8848: imagecopyresized() error refers to the wrong argument

Author: cmb69

ext/gd/gd.c

@@ -3013,22 +3013,22 @@ PHP_FUNCTION(imagecopyresized)
 	dstW = DW;
 
 	if (dstW <= 0) {
-		zend_argument_value_error(3, "must be greater than 0");
+		zend_argument_value_error(7, "must be greater than 0");
 		RETURN_THROWS();
 	}
 
 	if (dstH <= 0) {
-		zend_argument_value_error(4, "must be greater than 0");
+		zend_argument_value_error(8, "must be greater than 0");
 		RETURN_THROWS();
 	}
 
 	if (srcW <= 0) {
-		zend_argument_value_error(5, "must be greater than 0");
+		zend_argument_value_error(9, "must be greater than 0");
 		RETURN_THROWS();
 	}
 
 	if (srcH <= 0) {
-		zend_argument_value_error(6, "must be greater than 0");
+		zend_argument_value_error(10, "must be greater than 0");
 		RETURN_THROWS();
 	}
 

ext/gd/tests/gh8848.phpt

@@ -0,0 +1,31 @@
+--TEST--
+GH-8848 (imagecopyresized() error refers to the wrong argument)
+--SKIPIF--
+<?php
+if (!extension_loaded("gd")) die("skip gd extension not available");
+?>
+--FILE--
+<?php
+$image1 = imagecreatetruecolor(1, 1);
+$image2 = imagecreatetruecolor(1, 1);
+
+$argslist = [
+    [0, 1, 1, 1],
+    [1, 0, 1, 1],
+    [1, 1, 0, 1],
+    [1, 1, 1, 0],
+];
+
+foreach ($argslist as $args) {
+    try {
+        imagecopyresized($image1, $image2, 1, 1, 1, 1, ...$args);
+    } catch (ValueError $ex) {
+        echo $ex->getMessage(), PHP_EOL;
+    }
+}
+?>
+--EXPECT--
+imagecopyresized(): Argument #7 ($dst_width) must be greater than 0
+imagecopyresized(): Argument #8 ($dst_height) must be greater than 0
+imagecopyresized(): Argument #9 ($src_width) must be greater than 0
+imagecopyresized(): Argument #10 ($src_height) must be greater than 0