Bugfix: prevent crash with current source when reordering

Mixer.cpp

@@ -772,6 +772,19 @@ void Mixer::setCurrentIndex(int index)
     setCurrentSource( session_->at(index) );
 }
 
+void Mixer::moveIndex (int current_index, int target_index)
+{
+    // remember ptr to current source
+    Source *previous_current_source_ = currentSource();
+
+    // change order
+    session_->move(current_index, target_index);
+
+    // restore current
+    unsetCurrentSource();
+    setCurrentSource(previous_current_source_);
+}
+
 void Mixer::setCurrentNext()
 {
     if (session_->numSource() > 0) {
@@ -831,11 +844,10 @@ int Mixer::indexCurrentSource()
 
 Source *Mixer::currentSource()
 {
-    if ( current_source_ == session_->end() )
+    if ( current_source_ != session_->end() )
+        return (*current_source_);
+    else
         return nullptr;
-    else {
-        return *(current_source_);
-    }
 }
 
 // management of view

Mixer.h

@@ -73,6 +73,7 @@ public:
     void unsetCurrentSource ();
 
     void setCurrentIndex (int index);
+    void moveIndex (int current_index, int target_index);
     int  indexCurrentSource ();
 
     // browsing into sources

SessionCreator.cpp

@@ -16,6 +16,7 @@
 #include "ImageShader.h"
 #include "ImageProcessingShader.h"
 #include "MediaPlayer.h"
+#include "SystemToolkit.h"
 
 #include <tinyxml2.h>
 #include "tinyxml2Toolkit.h"
@@ -26,12 +27,13 @@ std::string SessionCreator::info(const std::string& filename)
 {
     std::string ret = "";
 
+    // if the file exists
+    if (SystemToolkit::file_exists(filename)) {
+        // try to load the file
         XMLDocument doc;
         XMLError eResult = doc.LoadFile(filename.c_str());
-    if ( XMLResultError(eResult)) {
-        Log::Warning("%s could not be openned.", filename.c_str());
-        return ret;
-    }
+        // silently ignore on error
+        if ( !XMLResultError(eResult, false)) {
 
             XMLElement *header = doc.FirstChildElement(APP_NAME);
             if (header != nullptr && header->Attribute("date") != 0) {
@@ -48,6 +50,8 @@ std::string SessionCreator::info(const std::string& filename)
                 }
 
             }
+        }
+    }
 
     return ret;
 }

UserInterfaceManager.cpp

@@ -1582,19 +1582,22 @@ void MediaController::setMediaPlayer(MediaPlayer *mp)
 void MediaController::followCurrentSource()
 {
     Source *s = Mixer::manager().currentSource();
-    if ( s != nullptr) {
-        MediaSource *ms = dynamic_cast<MediaSource *>(s);
-        if (ms) {
+    MediaSource *ms = nullptr;
+
+    if ( s != nullptr)
+        ms = dynamic_cast<MediaSource *>(s);
+
+    if ( ms != nullptr) {
         // update the internal mediaplayer if changed
         if (mp_ != ms->mediaplayer()) {
             mp_ = ms->mediaplayer();
             media_playing_mode_ = mp_->isPlaying();
         }
-        } else {
+    }
+    else {
         mp_ = nullptr;
         media_playing_mode_ = false;
     }
-    }
 }
 
 
@@ -2153,11 +2156,11 @@ void Navigator::Render()
                         if (const ImGuiPayload* payload = ImGui::AcceptDragDropPayload("DND_SOURCE"))
                         {
                             if ( payload->DataSize == sizeof(int) ) {
+                                // drop means move index and reorder
                                 int payload_index = *(const int*)payload->Data;
-                                int current_source_index = Mixer::manager().indexCurrentSource();
-                                Mixer::manager().session()->move(payload_index, index);
-                                if (payload_index == current_source_index)
-                                    applyButtonSelection(index);
+                                Mixer::manager().moveIndex(payload_index, index);
+                                // index of current source changed
+                                applyButtonSelection(Mixer::manager().indexCurrentSource());
                             }
                         }
                         ImGui::EndDragDropTarget();
@@ -2831,7 +2834,7 @@ void Navigator::RenderMainPannel()
         for(auto it = sessions_list.begin(); it != sessions_list.end(); it++) {
             std::string sessionfilename(*it);
             if (sessionfilename.empty())
-                break;
+                continue;
             std::string shortname = SystemToolkit::filename(*it);
             if (ImGui::Selectable( shortname.c_str(), false, ImGuiSelectableFlags_AllowDoubleClick )) {
                 if (ImGui::IsMouseDoubleClicked(ImGuiMouseButton_Left) || file_selected == it) {
@@ -2857,7 +2860,7 @@ void Navigator::RenderMainPannel()
                     file_info.clear();
                     file_selected = sessions_list.end();
                 }
-                if (!file_info.empty()) {
+                else if (!file_info.empty()) {
                     ImGui::BeginTooltip();
                     ImGui::Text("%s", file_info.c_str());
                     ImGui::EndTooltip();

tinyxml2Toolkit.cpp

@@ -237,11 +237,12 @@ bool tinyxml2::XMLSaveDoc(XMLDocument * const doc, std::string filename)
     return !XMLResultError(eResult);
 }
 
-bool tinyxml2::XMLResultError(int result)
+bool tinyxml2::XMLResultError(int result, bool verbose)
 {
     XMLError xmlresult = (XMLError) result;
     if ( xmlresult != XML_SUCCESS)
     {
+        if (verbose)
             Log::Info("XML error %i: %s", result, tinyxml2::XMLDocument::ErrorIDToName(xmlresult));
         return true;
     }

tinyxml2Toolkit.h

@@ -29,7 +29,7 @@ XMLElement *XMLElementEncodeArray(XMLDocument *doc, const void *array, uint arra
 bool XMLElementDecodeArray(XMLElement *elem, void *array, uint arraysize);
 
 bool XMLSaveDoc(tinyxml2::XMLDocument * const doc, std::string filename);
-bool XMLResultError(int result);
+bool XMLResultError(int result, bool verbose = true);
 
 }