guiScalingFilter: Fix most memory leaks (#12256)

Calls to the cache function ended up creating a new texture regardless whether
the texture is already cached.

2 files changed, 11 insertions, 3 deletions

diff --git a/src/client/client.cpp b/src/client/client.cpp
index 0a1fc73d1..cb556c1ce 100644
--- a/src/client/client.cpp
+++ b/src/client/client.cpp
@@ -334,6 +334,8 @@ Client::~Client()
 	// cleanup 3d model meshes on client shutdown
 	m_rendering_engine->cleanupMeshCache();
 
+	guiScalingCacheClear();
+
 	delete m_minimap;
 	m_minimap = nullptr;
 
diff --git a/src/client/guiscalingfilter.cpp b/src/client/guiscalingfilter.cpp
index 232219237..de122becf 100644
--- a/src/client/guiscalingfilter.cpp
+++ b/src/client/guiscalingfilter.cpp
@@ -43,6 +43,10 @@ void guiScalingCache(const io::path &key, video::IVideoDriver *driver, video::II
 {
 	if (!g_settings->getBool("gui_scaling_filter"))
 		return;
+
+	if (g_imgCache.find(key) != g_imgCache.end())
+		return; // Already cached.
+
 	video::IImage *copied = driver->createImage(value->getColorFormat(),
 			value->getDimension());
 	value->copyTo(copied);
@@ -90,14 +94,16 @@ video::ITexture *guiScalingResizeCached(video::IVideoDriver *driver,
 	io::path scalename = origname + "@guiScalingFilter:" + rectstr;
 
 	// Search for existing scaled texture.
-	video::ITexture *scaled = g_txrCache[scalename];
+	auto it_txr = g_txrCache.find(scalename);
+	video::ITexture *scaled = (it_txr != g_txrCache.end()) ? it_txr->second : nullptr;
 	if (scaled)
 		return scaled;
 
 	// Try to find the texture converted to an image in the cache.
 	// If the image was not found, try to extract it from the texture.
-	video::IImage* srcimg = g_imgCache[origname];
-	if (srcimg == NULL) {
+	auto it_img = g_imgCache.find(origname);
+	video::IImage *srcimg = (it_img != g_imgCache.end()) ? it_img->second : nullptr;
+	if (!srcimg) {
 		if (!g_settings->getBool("gui_scaling_filter_txr2img"))
 			return src;
 		srcimg = driver->createImageFromData(src->getColorFormat(),