From eafac57d1d684ce9f26466c296789565d85b07ec Mon Sep 17 00:00:00 2001
From: Thomas Jentzsch <tjentzsch@yahoo.de>
Date: Thu, 14 Oct 2021 19:35:49 +0200
Subject: [PATCH] fixes #834 (major renderer memory leak)

---
 src/common/FBBackendSDL2.cxx | 15 ++++++---------
 src/common/FBBackendSDL2.hxx |  4 +---
 src/gui/Dialog.cxx           |  2 +-
 3 files changed, 8 insertions(+), 13 deletions(-)

diff --git a/src/common/FBBackendSDL2.cxx b/src/common/FBBackendSDL2.cxx
index 566d9d713..e205ac28b 100644
--- a/src/common/FBBackendSDL2.cxx
+++ b/src/common/FBBackendSDL2.cxx
@@ -230,7 +230,6 @@ bool FBBackendSDL2::setVideoMode(const VideoModeHandler::Mode& mode,
     return false;
 
   const bool fullScreen = mode.fsIndex != -1;
-  bool forceCreateRenderer = false;
   Int32 displayIndex = std::min(myNumDisplays - 1, winIdx);
 
   int posX, posY;
@@ -292,6 +291,9 @@ bool FBBackendSDL2::setVideoMode(const VideoModeHandler::Mode& mode,
     if(d != displayIndex || uInt32(w) != mode.screenS.w ||
        uInt32(h) != mode.screenS.h || adaptRefresh)
     {
+      // Renderer has to be destroyed *before* the window gets destroyed to avoid memory leaks
+      SDL_DestroyRenderer(myRenderer);
+      myRenderer = nullptr;
       SDL_DestroyWindow(myWindow);
       myWindow = nullptr;
     }
@@ -305,7 +307,6 @@ bool FBBackendSDL2::setVideoMode(const VideoModeHandler::Mode& mode,
   }
   else
   {
-    forceCreateRenderer = true;
     myWindow = SDL_CreateWindow(myScreenTitle.c_str(), posX, posY,
                                 mode.screenS.w, mode.screenS.h, flags);
     if(myWindow == nullptr)
@@ -337,7 +338,7 @@ bool FBBackendSDL2::setVideoMode(const VideoModeHandler::Mode& mode,
   }
 #endif
 
-  return createRenderer(forceCreateRenderer);
+  return createRenderer();
 }
 
 // - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
@@ -400,16 +401,15 @@ bool FBBackendSDL2::adaptRefreshRate(Int32 displayIndex,
 }
 
 // - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
-bool FBBackendSDL2::createRenderer(bool force)
+bool FBBackendSDL2::createRenderer()
 {
   ASSERT_MAIN_THREAD;
 
   // A new renderer is only created when necessary:
-  // - new myWindow (force = true)
   // - no renderer existing
   // - different renderer flags
   // - different renderer name
-  bool recreate = force || myRenderer == nullptr;
+  bool recreate = myRenderer == nullptr;
   uInt32 renderFlags = SDL_RENDERER_ACCELERATED;
   const string& video = myOSystem.settings().getString("video");  // Render hint
   SDL_RendererInfo renderInfo;
@@ -426,9 +426,6 @@ bool FBBackendSDL2::createRenderer(bool force)
   if(recreate)
   {
     //cerr << "Create new renderer for buffer type #" << int(myBufferType) << endl;
-    if(myRenderer)
-      SDL_DestroyRenderer(myRenderer);
-
     if(video != "")
       SDL_SetHint(SDL_HINT_RENDER_DRIVER, video.c_str());
 
diff --git a/src/common/FBBackendSDL2.hxx b/src/common/FBBackendSDL2.hxx
index 32da839d2..5ada52c6c 100644
--- a/src/common/FBBackendSDL2.hxx
+++ b/src/common/FBBackendSDL2.hxx
@@ -208,11 +208,9 @@ class FBBackendSDL2 : public FBBackend
     /**
       Create a new renderer if required.
 
-      @param force  If true, force new renderer creation
-
       @return  False on any errors, else true
     */
-    bool createRenderer(bool force);
+    bool createRenderer();
 
     /**
       This method must be called after all drawing is done, and indicates
diff --git a/src/gui/Dialog.cxx b/src/gui/Dialog.cxx
index c615ed8fb..9b7f59f64 100644
--- a/src/gui/Dialog.cxx
+++ b/src/gui/Dialog.cxx
@@ -346,7 +346,7 @@ void Dialog::render()
     _renderCallback();
 
   // A dialog is still on top if a non-shading dialog (e.g. ContextMenu)
-  // is opended above it.
+  // is opened above it.
   bool onTop = parent().myDialogStack.top() == this
     || (parent().myDialogStack.get(parent().myDialogStack.size() - 2) == this
         && !parent().myDialogStack.top()->isShading());