ZP-853 Allow a return value of false for single folders when calling

Backend->GetFolderStat(). In this case, in Sync the exporter will always
run for these folders. In Ping the initial checkup (generate fake
changes and force a Sync on this folder if the stat does not match or
expired) can not be executed.

Released under the Affero GNU General Public License (AGPL) version 3.

src/lib/core/synccollections.php

@@ -518,7 +518,8 @@ class SyncCollections implements Iterator {
                 }
 
                 // check if the folder stat changed since the last sync, if so generate a change for it (only on first run)
-                if ($this->waitingTime == 0 && ZPush::GetBackend()->HasFolderStats() && $spa->IsExporterRunRequired(ZPush::GetBackend()->GetFolderStat($store, $spa->GetFolderId()), true)) {
+                $currentFolderStat = ZPush::GetBackend()->GetFolderStat($store, $spa->GetFolderId());
+                if ($this->waitingTime == 0 && ZPush::GetBackend()->HasFolderStats() && $currentFolderStat !== false && $spa->IsExporterRunRequired($currentFolderStat, true)) {
                     $this->changes[$spa->GetFolderId()] = 1;
                 }
             }

src/lib/core/syncparameters.php

@@ -287,10 +287,17 @@ class SyncParameters extends StateObject {
      * @return boolean
      */
     public function IsExporterRunRequired($currentFolderStat, $doLog = false) {
-        $run = ! ($this->HasFolderStat() && $currentFolderStat === $this->GetFolderStat() && time() < $this->GetFolderStatTimeout());
+        // if the backend returned false as folderstat, we have to run the exporter
+        if ($currentFolderStat === false)  {
+            $run = true;
+        }
+        else {
+            // check if the folderstat differs from the saved one or expired
+            $run = ! ($this->HasFolderStat() && $currentFolderStat === $this->GetFolderStat() && time() < $this->GetFolderStatTimeout());
+        }
         if ($doLog) {
             $expDate = ($this->HasFolderStatTimeout()) ? date('Y-m-d H:i:s', $this->GetFolderStatTimeout()) : "not set";
-            ZLog::Write(LOGLEVEL_DEBUG, sprintf("SyncParameters->IsExporterRunRequired(): %s - current: %s - saved: %s - expiring: %s", Utils::PrintAsString($run), $currentFolderStat, Utils::PrintAsString($this->GetFolderStat()), $expDate));
+            ZLog::Write(LOGLEVEL_DEBUG, sprintf("SyncParameters->IsExporterRunRequired(): %s - current: %s - saved: %s - expiring: %s", Utils::PrintAsString($run), Utils::PrintAsString($currentFolderStat), Utils::PrintAsString($this->GetFolderStat()), $expDate));
         }
         return $run;
     }

src/lib/request/sync.php

@@ -741,7 +741,7 @@ class Sync extends RequestProcessor {
                 if ($setupExporter && self::$backend->HasFolderStats()) {
                     // check if the folder stats changed -> if not, don't setup the exporter, there are no changes!
                     $newFolderStat = self::$backend->GetFolderStat(ZPush::GetAdditionalSyncFolderStore($spa->GetFolderId()), $spa->GetFolderId());
-                    if (! $spa->IsExporterRunRequired($newFolderStat, true)) {
+                    if ($newFolderStat !== false && ! $spa->IsExporterRunRequired($newFolderStat, true)) {
                         $changecount = 0;
                         $setupExporter = false;
                         ZLog::Write(LOGLEVEL_DEBUG, "Sync(): Folder stat from the backend indicates that the folder did not change. Exporter will not run.");
@@ -828,7 +828,7 @@ class Sync extends RequestProcessor {
 
             // Fir AS 14.0+ omit output for folder, if there were no incoming or outgoing changes and no Fetch
             if (Request::GetProtocolVersion() >= 14.0 && ! $spa->HasNewSyncKey() && $changecount == 0 && empty($actiondata["fetchids"]) && $status == SYNC_STATUS_SUCCESS &&
-                    ! $spa->IsExporterRunRequired($newFolderStat)) {
+                    ($newFolderStat === false || ! $spa->IsExporterRunRequired($newFolderStat))) {
                 ZLog::Write(LOGLEVEL_DEBUG, sprintf("HandleSync: No changes found for %s folder id '%s'. Omitting output.", $spa->GetContentClass(), $spa->GetFolderId()));
                 continue;
             }