Forward port zendframework/zendframework#5893

src/Json.php

@@ -369,10 +369,12 @@ public static function prettyPrint($json, $options = array())
             } else {
                 $result .= ($inLiteral ?  '' : $prefix) . $token;
 
+                //remove escaped backslash sequences causing false positives in next check
+                $token = str_replace('\\', '', $token);
                 // Count # of unescaped double-quotes in token, subtract # of
                 // escaped double-quotes and if the result is odd then we are
                 // inside a string literal
-                if ((substr_count($token, "\"")-substr_count($token, "\\\"")) % 2 != 0) {
+                if ((substr_count($token, '"')-substr_count($token, '\\"')) % 2 != 0) {
                     $inLiteral = !$inLiteral;
                 }
             }

test/JsonTest.php

@@ -890,6 +890,19 @@ public function testJsonPrettyPrintWorksWithArrayNotationInStringLiteral()
         $this->assertSame($expected, $pretty);
     }
 
+    public function testPrettyPrintDoublequoteFollowingEscapedBackslashShouldNotBeTreatedAsEscaped()
+    {
+        $this->assertEquals(
+            "[\n\t1,\n\t\"\\\\\",\n\t3\n]",
+            Json\Json::prettyPrint(Json\Json::encode(array(1, '\\', 3)))
+        );
+
+        $this->assertEquals(
+            "{\n\t\"a\":\"\\\\\"\n}",
+           Json\Json::prettyPrint(Json\Json::encode(array('a' => '\\')))
+        );
+    }
+
     /**
      * @group ZF-11167
      */