ZP-481 #comment read supported contents only if there is content, else ignore supported completely

git-svn-id: https://z-push.org/svn/z-push/trunk@1790 b7dd7b3b-3a3c-0410-9da9-bee62a6cc5b5

src/lib/request/sync.php

@@ -175,17 +175,22 @@ class Sync extends RequestProcessor {
                         ZLog::Write(LOGLEVEL_WARN, "Not possible to determine class of request. Request did not contain class and apparently there is an issue with the HierarchyCache.");
 
                     // SUPPORTED properties
-                    if(self::$decoder->getElementStartTag(SYNC_SUPPORTED)) {
-                        $supfields = array();
-                        while(1) {
-                            $el = self::$decoder->getElement();
+                    if(($se = self::$decoder->getElementStartTag(SYNC_SUPPORTED)) !== false) {
+                        // ZP-481: LG phones send an empty supported tag, so only read the contents if available here
+                        // if <Supported/> is received, it's as no supported fields would have been sent at all.
+                        // unsure if this is the correct approach, or if in this case some default list should be used
+                        if ($se[EN_FLAGS] & EN_FLAGS_CONTENT) {
+                            $supfields = array();
+                            while(1) {
+                                $el = self::$decoder->getElement();
 
-                            if($el[EN_TYPE] == EN_TYPE_ENDTAG)
-                                break;
-                            else
-                                $supfields[] = $el[EN_TAG];
+                                if($el[EN_TYPE] == EN_TYPE_ENDTAG)
+                                    break;
+                                else
+                                    $supfields[] = $el[EN_TAG];
+                            }
+                            self::$deviceManager->SetSupportedFields($spa->GetFolderId(), $supfields);
                         }
-                        self::$deviceManager->SetSupportedFields($spa->GetFolderId(), $supfields);
                     }
 
                     // Deletes as moves can be an empty tag as well as have value