Fixed clipboard paste memory leak in SDL examples. (#1803)

examples/sdl_opengl2_example/imgui_impl_sdl_gl2.cpp

@@ -48,6 +48,7 @@ static Uint64       g_Time = 0;
 static bool         g_MousePressed[3] = { false, false, false };
 static GLuint       g_FontTexture = 0;
 static SDL_Cursor*  g_MouseCursors[ImGuiMouseCursor_COUNT] = { 0 };
+static char*        g_ClipboardTextData = NULL;
 
 // OpenGL2 Render function.
 // (this used to be set in io.RenderDrawListsFn and called by ImGui::Render(), but you can now call this directly from your main loop)
@@ -135,7 +136,10 @@ void ImGui_ImplSdlGL2_RenderDrawData(ImDrawData* draw_data)
 
 static const char* ImGui_ImplSdlGL2_GetClipboardText(void*)
 {
-    return SDL_GetClipboardText();
+    if (g_ClipboardTextData) SDL_free(g_ClipboardTextData);
+    g_ClipboardTextData = SDL_GetClipboardText();
+
+    return g_ClipboardTextData;
 }
 
 static void ImGui_ImplSdlGL2_SetClipboardText(void*, const char* text)
@@ -285,6 +289,9 @@ void ImGui_ImplSdlGL2_Shutdown()
         SDL_FreeCursor(g_MouseCursors[cursor_n]);
     memset(g_MouseCursors, 0, sizeof(g_MouseCursors));
 
+    // Remove previously allocated clipboard text data
+    if (g_ClipboardTextData) SDL_free(g_ClipboardTextData);
+
     // Destroy OpenGL objects
     ImGui_ImplSdlGL2_InvalidateDeviceObjects();
 }

examples/sdl_opengl3_example/imgui_impl_sdl_gl3.cpp

@@ -51,6 +51,7 @@
 static Uint64       g_Time = 0;
 static bool         g_MousePressed[3] = { false, false, false };
 static SDL_Cursor*  g_MouseCursors[ImGuiMouseCursor_COUNT] = { 0 };
+static char*        g_ClipboardTextData = NULL;
 
 // OpenGL data
 static char         g_GlslVersion[32] = "#version 150";
@@ -183,7 +184,10 @@ void ImGui_ImplSdlGL3_RenderDrawData(ImDrawData* draw_data)
 
 static const char* ImGui_ImplSdlGL3_GetClipboardText(void*)
 {
-    return SDL_GetClipboardText();
+    if (g_ClipboardTextData) SDL_free(g_ClipboardTextData);
+    g_ClipboardTextData = SDL_GetClipboardText();
+
+    return g_ClipboardTextData;
 }
 
 static void ImGui_ImplSdlGL3_SetClipboardText(void*, const char* text)
@@ -418,6 +422,9 @@ void ImGui_ImplSdlGL3_Shutdown()
         SDL_FreeCursor(g_MouseCursors[cursor_n]);
     memset(g_MouseCursors, 0, sizeof(g_MouseCursors));
 
+    // Remove previously allocated clipboard text data
+    if (g_ClipboardTextData) SDL_free(g_ClipboardTextData);
+
     // Destroy OpenGL objects
     ImGui_ImplSdlGL3_InvalidateDeviceObjects();
 }