ext/curl: Handle empty Content-Type response by setting content_type to false

- Ensures consistent behavior when Content-Type is missing

Author: MarcusXavierr

ext/curl/interface.c

@@ -2501,7 +2501,7 @@ PHP_FUNCTION(curl_getinfo)
 				CAAS("content_type", s_code);
 			} else {
 				zval retnull;
-				ZVAL_NULL(&retnull);
+				ZVAL_FALSE(&retnull);
 				CAAZ("content_type", &retnull);
 			}
 		}

ext/curl/tests/bug16929.phpt

@@ -0,0 +1,32 @@
+--TEST--
+Bug #16929 (curl_getinfo($ch, CURLINFO_CONTENT_TYPE) returns false when Content-Type header is not set)
+--EXTENSIONS--
+curl
+--FILE--
+<?php
+
+include 'server.inc';
+$host = curl_cli_server_start();
+$ch = curl_init();
+$url = "{$host}/get.inc?test=emptycontenttype";
+
+curl_setopt($ch, CURLOPT_URL, $url);
+curl_setopt($ch, CURLOPT_RETURNTRANSFER, $url);
+curl_exec($ch);
+
+$ct = curl_getinfo($ch, CURLINFO_CONTENT_TYPE);
+
+var_dump($ct);
+
+$info = curl_getinfo($ch)['content_type'];
+
+var_dump($info);
+
+curl_close($ch);
+
+
+curl_close($ch);
+?>
+--EXPECTF--
+bool(false)
+bool(false)

ext/curl/tests/responder/get.inc

@@ -29,6 +29,9 @@
     case 'contenttype':
       header('Content-Type: text/plain;charset=utf-8');
       break;
+    case 'emptycontenttype':
+      header('Content-Type: ');
+      break;
     case 'file':
       if (isset($_FILES['file'])) {
           echo $_FILES['file']['name'] . '|' . $_FILES['file']['type'] . '|' . $_FILES['file']['size'];