Fix deadlock on joins cache

Fixes #43287 The critical section was called recursively by a call form the model connected to joinedFieldsChanged. By moving the mutex into a scope we can safely release it before emitting the signal.
qgis · May 28, 2021 · 3b612b0 · 3b612b0
1 parent 32995d5
commit 3b612b0
Showing 1 changed file with 10 additions and 8 deletions.
diff --git a/src/core/vector/qgsvectorlayerjoinbuffer.cpp b/src/core/vector/qgsvectorlayerjoinbuffer.cpp
@@ -100,19 +100,21 @@ bool QgsVectorLayerJoinBuffer::addJoin( const QgsVectorLayerJoinInfo &joinInfo )
 
 bool QgsVectorLayerJoinBuffer::removeJoin( const QString &joinLayerId )
 {
-  QMutexLocker locker( &mMutex );
   bool res = false;
-  for ( int i = 0; i < mVectorJoins.size(); ++i )
   {
-    if ( mVectorJoins.at( i ).joinLayerId() == joinLayerId )
+    QMutexLocker locker( &mMutex );
+    for ( int i = 0; i < mVectorJoins.size(); ++i )
     {
-      if ( QgsVectorLayer *vl = mVectorJoins.at( i ).joinLayer() )
+      if ( mVectorJoins.at( i ).joinLayerId() == joinLayerId )
       {
-        disconnect( vl, &QgsVectorLayer::updatedFields, this, &QgsVectorLayerJoinBuffer::joinedLayerUpdatedFields );
-      }
+        if ( QgsVectorLayer *vl = mVectorJoins.at( i ).joinLayer() )
+        {
+          disconnect( vl, &QgsVectorLayer::updatedFields, this, &QgsVectorLayerJoinBuffer::joinedLayerUpdatedFields );
+        }
 
-      mVectorJoins.removeAt( i );
-      res = true;
+        mVectorJoins.removeAt( i );
+        res = true;
+      }
     }
   }