Don't use Preferences in background threads

src/app/crash/backup_observer.cpp

@@ -1,5 +1,5 @@
 // Aseprite
-// Copyright (C) 2018  Igara Studio S.A.
+// Copyright (C) 2018-2019  Igara Studio S.A.
 // Copyright (C) 2001-2018  David Capello
 //
 // This program is distributed under the terms of
@@ -60,6 +60,7 @@ BackupObserver::BackupObserver(Session* session, Context* ctx)
   : m_session(session)
   , m_ctx(ctx)
   , m_done(false)
+  , m_period(Preferences::instance().general.dataRecoveryPeriod())
   , m_thread(base::Bind<void>(&BackupObserver::backgroundThread, this))
 {
   m_ctx->add_observer(this);
@@ -97,7 +98,7 @@ void BackupObserver::onRemoveDocument(Doc* document)
 
 void BackupObserver::backgroundThread()
 {
-  int normalPeriod = int(60.0*Preferences::instance().general.dataRecoveryPeriod());
+  int normalPeriod = int(60.0*m_period);
   int lockedPeriod = 5;
 #ifdef TEST_BACKUPS_WITH_A_SHORT_PERIOD
   normalPeriod = 5;

src/app/crash/backup_observer.h

@@ -1,4 +1,5 @@
 // Aseprite
+// Copyright (C) 2019  Igara Studio S.A.
 // Copyright (C) 2001-2018  David Capello
 //
 // This program is distributed under the terms of
@@ -42,6 +43,7 @@ namespace crash {
     Context* m_ctx;
     std::vector<Doc*> m_documents;
     bool m_done;
+    int m_period;
     base::thread m_thread;
   };
 

src/app/file/file.cpp

@@ -737,7 +737,7 @@ void FileOp::operate(IFileOpProgress* progress)
 
       // For each frame in the sprite.
       render::Render render;
-      render.setNewBlend(Preferences::instance().experimental.newBlend());
+      render.setNewBlend(m_newBlend);
 
       frame_t outputFrame = 0;
       for (frame_t frame : m_roi.selectedFrames()) {
@@ -913,7 +913,7 @@ void FileOp::postLoad()
   app::gen::ColorProfileBehavior behavior =
     app::gen::ColorProfileBehavior::DISABLE;
 
-  if (Preferences::instance().color.manage()) {
+  if (m_preserveColorProfile) {
     // Embedded color profile
     if (this->hasEmbeddedColorProfile()) {
       behavior = Preferences::instance().color.filesWithProfile();
@@ -1186,9 +1186,9 @@ FileOp::FileOp(FileOpType type, Context* context)
   , m_oneframe(false)
   , m_createPaletteFromRgba(false)
   , m_ignoreEmpty(false)
-  , m_preserveColorProfile(
-      Preferences::instance().color.manage())
+  , m_preserveColorProfile(Preferences::instance().color.manage())
   , m_embeddedColorProfile(false)
+  , m_newBlend(Preferences::instance().experimental.newBlend())
 {
   m_seq.palette = nullptr;
   m_seq.image.reset();

src/app/file/file.h

@@ -208,6 +208,10 @@ namespace app {
     // True if the file contained a color profile when it was loaded.
     bool m_embeddedColorProfile;
 
+    // True if we should render each frame to save it with the new
+    // blend mode.
+    bool m_newBlend;
+
     base::SharedPtr<FormatOptions> m_formatOptions;
 
     // Data for sequences.

src/app/pref/preferences.cpp

@@ -17,6 +17,7 @@
 #include "app/tools/tool.h"
 #include "doc/sprite.h"
 #include "os/system.h"
+#include "ui/system.h"
 
 namespace app {
 
@@ -25,6 +26,10 @@ static Preferences* singleton = nullptr;
 // static
 Preferences& Preferences::instance()
 {
+  // Preferences can be used only from the main UI thread. In other
+  // case access to std::map<> could crash the program.
+  ui::assert_ui_thread();
+
   ASSERT(singleton);
   return *singleton;
 }

src/app/thumbnail_generator.cpp

@@ -90,8 +90,8 @@ private:
       // Load the file
       m_fop->operate(nullptr);
 
-      // Post load
-      m_fop->postLoad();
+      // Don't call post-load because postLoad() needs user interaction.
+      //m_fop->postLoad();
 
       // Convert the loaded document into the os::Surface.
       const Sprite* sprite =