QHostInfo: Fix a crash when a new request is pushed while resolving.

The loop looking for posponedLookup in the lookup thread wasn't locking
the mutex before trying to access/modify the list.

Reviewed-by: Andreas Kling
(cherry picked from commit 45c2ac4f1e1218f595b1d21691c8dec4eaa1a021)

1 files changed, 11 insertions, 8 deletions

diff --git a/src/network/kernel/qhostinfo.cpp b/src/network/kernel/qhostinfo.cpp
index 348b0d2..41a9512 100644
--- a/src/network/kernel/qhostinfo.cpp
+++ b/src/network/kernel/qhostinfo.cpp
@@ -468,14 +468,17 @@ void QHostInfoRunnable::run()
     resultEmitter.emitResultsReady(hostInfo);
 
     // now also iterate through the postponed ones
-    QMutableListIterator<QHostInfoRunnable*> iterator(manager->postponedLookups);
-    while (iterator.hasNext()) {
-        QHostInfoRunnable* postponed = iterator.next();
-        if (toBeLookedUp == postponed->toBeLookedUp) {
-            // we can now emit
-            iterator.remove();
-            hostInfo.setLookupId(postponed->id);
-            postponed->resultEmitter.emitResultsReady(hostInfo);
+    {
+        QMutexLocker locker(&manager->mutex);
+        QMutableListIterator<QHostInfoRunnable*> iterator(manager->postponedLookups);
+        while (iterator.hasNext()) {
+            QHostInfoRunnable* postponed = iterator.next();
+            if (toBeLookedUp == postponed->toBeLookedUp) {
+                // we can now emit
+                iterator.remove();
+                hostInfo.setLookupId(postponed->id);
+                postponed->resultEmitter.emitResultsReady(hostInfo);
+            }
         }
     }