Fixed crash when taking screenshot with scaled graphics

Because the allocated surface was based on the unscaled size, writing
the actual pixels was overwriting random memory.

2 files changed, 28 insertions, 15 deletions

diff --git a/src/game.cpp b/src/game.cpp
index 0bf2e48a..d2bd1430 100644
--- a/src/game.cpp
+++ b/src/game.cpp
@@ -86,7 +86,6 @@
 
 #include <fstream>
 #include <sstream>
-#include <string>
 
 Joystick *joystick;
 
@@ -286,10 +285,17 @@ static bool saveScreenshot()
         actorSpriteManager->updatePlayerNames();
     }
 
+    if (!screenshot)
+    {
+        SERVER_NOTICE(_("Could not take screenshot!"))
+        logger->log("Error: could not take screenshot.");
+        return false;
+    }
+
     // Search for an unused screenshot name
-    std::stringstream filenameSuffix;
-    std::stringstream filename;
-    std::fstream testExists;
+    std::ostringstream filenameSuffix;
+    std::ostringstream filename;
+    std::ifstream testExists;
     std::string screenshotDirectory = Client::getScreenshotDirectory();
     bool found = false;
 
@@ -305,12 +311,11 @@ static bool saveScreenshot()
     {
         screenshotCount++;
         filenameSuffix.str(std::string());
-        filename.str(std::string());
-        filename << screenshotDirectory << "/";
         filenameSuffix << branding.getValue("appShort", "Mana")
                        << "_Screenshot_" << screenshotCount << ".png";
-        filename << filenameSuffix.str();
-        testExists.open(filename.str().c_str(), std::ios::in);
+        filename.str(std::string());
+        filename << screenshotDirectory << "/" << filenameSuffix.str();
+        testExists.open(filename.str());
         found = !testExists.is_open();
         testExists.close();
     }
@@ -320,7 +325,7 @@ static bool saveScreenshot()
 
     if (success)
     {
-        std::stringstream chatlogentry;
+        std::ostringstream chatlogentry;
         // TODO: Make it one complete gettext string below
         chatlogentry << _("Screenshot saved as ") << filenameSuffix.str();
         SERVER_NOTICE(chatlogentry.str())
diff --git a/src/sdlgraphics.cpp b/src/sdlgraphics.cpp
index a2fc2268..d3ff72e2 100644
--- a/src/sdlgraphics.cpp
+++ b/src/sdlgraphics.cpp
@@ -236,13 +236,21 @@ SDL_Surface *SDLGraphics::getScreenshot()
 #endif
     int amask = 0x00000000;
 
-    SDL_Surface *screenshot = SDL_CreateRGBSurface(0, mWidth,
-            mHeight, 24, rmask, gmask, bmask, amask);
+    int width, height;
+    if (SDL_GetRendererOutputSize(mRenderer, &width, &height) != 0)
+        return nullptr;
 
-    SDL_RenderReadPixels(mRenderer, nullptr,
-                         screenshot->format->format,
-                         screenshot->pixels,
-                         screenshot->pitch);
+    SDL_Surface *screenshot = SDL_CreateRGBSurface(0, width, height, 24,
+                                                   rmask, gmask, bmask, amask);
+
+    if (SDL_RenderReadPixels(mRenderer, nullptr,
+                             screenshot->format->format,
+                             screenshot->pixels,
+                             screenshot->pitch) != 0)
+    {
+        SDL_FreeSurface(screenshot);
+        screenshot = nullptr;
+    }
 
     return screenshot;
 }