Fix bug #71952: Corruption inside imageaffinematrixget

NEWS

@@ -16,6 +16,9 @@ PHP                                                                        NEWS
 - Date:
   . Fixed bug #71889 (DateInterval::format Segmentation fault). (Thomas Punt)
 
+- GD: 
+  . Fixed bug #71952 (Corruption inside imageaffinematrixget). (Stas)
+
 - OCI8:
   . Fixed bug #71422 (Fix ORA-01438: value larger than specified precision
     allowed for this column). (Chris Jones)

ext/gd/gd.c

@@ -5362,7 +5362,10 @@ PHP_FUNCTION(imageaffinematrixget)
 				php_error_docref(NULL TSRMLS_CC, E_WARNING, "Number is expected as option");
 				RETURN_FALSE;
 			}
-			convert_to_double_ex(&options);
+			if(Z_TYPE_P(options) != IS_DOUBLE) {
+				Z_ADDREF_P(options);
+				convert_to_double_ex(&options);
+			}
 			angle = Z_DVAL_P(options);
 
 			if (type == GD_AFFINE_SHEAR_HORIZONTAL) {

ext/gd/tests/bug71952.phpt

@@ -0,0 +1,14 @@
+--TEST--
+Bug #71952 (Corruption inside imageaffinematrixget)
+--SKIPIF--
+<?php
+	if(!extension_loaded('gd')){ die('skip gd extension not available'); }
+?>
+--FILE--
+<?php
+$vals=[str_repeat("A","200"),0,1,2,3,4,5,6,7,8,9];
+imageaffinematrixget(4,$vals[0]);
+var_dump($vals[0]);
+?>
+--EXPECTF--
+string(200) "AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA"