couple breakpoint listing with source listing

the assumption is that pending breakpoints will only be resolved when
the source list changes. consequently it is pointless to update just
one of them.

src/plugins/debugger/gdb/gdbengine.cpp

@@ -879,7 +879,6 @@ void GdbEngine::updateAll()
 
 void GdbEngine::handleQuerySources(const GdbResponse &response)
 {
-    m_sourcesListUpdating = false;
     if (response.resultClass == GdbResultDone) {
         QMap<QString, QString> oldShortToFull = m_shortToFullName;
         m_shortToFullName.clear();
@@ -1153,8 +1152,6 @@ void GdbEngine::handleStop1(const GdbMi &data)
     QByteArray reason = data.findChild("reason").data();
     if (reason == "breakpoint-hit") {
         showStatusMessage(tr("Stopped at breakpoint."));
-        //debugMessage(_("HIT BREAKPOINT: " + frame.toString()));
-        postCommand(_("-break-list"), CB(handleBreakList));
     } else {
         if (reason == "signal-received"
             && theDebuggerBoolSetting(UseMessageBoxForSignals)) {
@@ -1765,6 +1762,8 @@ void GdbEngine::sendInsertBreakpoint(int index)
 
 void GdbEngine::handleBreakList(const GdbResponse &response)
 {
+    m_sourcesListUpdating = false;
+
     // 45^done,BreakpointTable={nr_rows="2",nr_cols="6",hdr=[
     // {width="3",alignment="-1",col_name="number",colhdr="Num"}, ...
     // body=[bkpt={number="1",type="breakpoint",disp="keep",enabled="y",
@@ -1965,11 +1964,6 @@ void GdbEngine::handleBreakInsert1(const GdbResponse &response)
     attemptBreakpointSynchronization(); // trigger "ready"
 }
 
-void GdbEngine::attemptBreakpointSynchronization2(const GdbResponse &)
-{
-    attemptBreakpointSynchronization();
-}
-
 void GdbEngine::attemptBreakpointSynchronization()
 {
     switch (state()) {
@@ -1985,9 +1979,11 @@ void GdbEngine::attemptBreakpointSynchronization()
     }
 
     // For best results, we rely on an up-to-date fullname mapping.
+    // The listing completion will retrigger us, so no futher action is needed.
     if (m_sourcesListOutdated) {
         reloadSourceFiles();
-        postCommand(_("p 5"), CB(attemptBreakpointSynchronization2));
+        return;
+    } else if (m_sourcesListUpdating) {
         return;
     }
 
@@ -2165,6 +2161,7 @@ void GdbEngine::reloadSourceFiles()
     m_sourcesListUpdating = true;
     m_sourcesListOutdated = false;
     postCommand(_("-file-list-exec-source-files"), NeedsStop, CB(handleQuerySources));
+    postCommand(_("-break-list"), CB(handleBreakList));
 }