Made default clipboard handlers for Win32 and OSX use a buffer inside the main context instead of a static buffer, so it can be freed properly on Shutdown. (#3110)

docs/CHANGELOG.txt

@@ -73,6 +73,8 @@ Other Changes:
   to a solution rather than encourage people to add braces in the codebase.
 - Misc: Added additional checks in EndFrame() to verify that io.KeyXXX values have not been
   tampered with between NewFrame() and EndFrame().
+- Misc: Made default clipboard handlers for Win32 and OSX use a buffer inside the main context
+  instead of a static buffer, so it can be freed properly on Shutdown. (#3110)
 - Misc, Freetype: Fixed support for IMGUI_STB_RECT_PACK_FILENAME compile time directive
   in imgui_freetype.cpp (matching support in the regular code path). (#3062) [@DonKult]
 - Metrics: Made Tools section more prominent. Showing wire-frame mesh directly hovering the ImDrawCmd

imgui.cpp

@@ -3985,7 +3985,7 @@ void ImGui::Shutdown(ImGuiContext* context)
     g.CurrentTabBarStack.clear();
     g.ShrinkWidthBuffer.clear();
 
-    g.PrivateClipboard.clear();
+    g.ClipboardHandlerData.clear();
     g.MenusIdSubmittedThisFrame.clear();
     g.InputTextState.ClearFreeMemory();
 
@@ -9805,10 +9805,11 @@ static void WindowSettingsHandler_WriteAll(ImGuiContext* ctx, ImGuiSettingsHandl
 #endif
 
 // Win32 clipboard implementation
+// We use g.ClipboardHandlerData for temporary storage to ensure it is freed on Shutdown()
 static const char* GetClipboardTextFn_DefaultImpl(void*)
 {
-    static ImVector<char> buf_local;
+    ImGuiContext& g = *GImGui;
-    buf_local.clear();
+    g.ClipboardHandlerData.clear();
     if (!::OpenClipboard(NULL))
         return NULL;
     HANDLE wbuf_handle = ::GetClipboardData(CF_UNICODETEXT);
@@ -9820,12 +9821,12 @@ static const char* GetClipboardTextFn_DefaultImpl(void*)
     if (const WCHAR* wbuf_global = (const WCHAR*)::GlobalLock(wbuf_handle))
     {
         int buf_len = ::WideCharToMultiByte(CP_UTF8, 0, wbuf_global, -1, NULL, 0, NULL, NULL);
-        buf_local.resize(buf_len);
+        g.ClipboardHandlerData.resize(buf_len);
-        ::WideCharToMultiByte(CP_UTF8, 0, wbuf_global, -1, buf_local.Data, buf_len, NULL, NULL);
+        ::WideCharToMultiByte(CP_UTF8, 0, wbuf_global, -1, g.ClipboardHandlerData.Data, buf_len, NULL, NULL);
     }
     ::GlobalUnlock(wbuf_handle);
     ::CloseClipboard();
-    return buf_local.Data;
+    return g.ClipboardHandlerData.Data;
 }
 
 static void SetClipboardTextFn_DefaultImpl(void*, const char* text)
@@ -9887,13 +9888,14 @@ static const char* GetClipboardTextFn_DefaultImpl(void*)
             CFDataRef cf_data;
             if (PasteboardCopyItemFlavorData(main_clipboard, item_id, CFSTR("public.utf8-plain-text"), &cf_data) == noErr)
             {
-                static ImVector<char> clipboard_text;
+                ImGuiContext& g = *GImGui;
+                g.ClipboardHandlerData.clear();
                 int length = (int)CFDataGetLength(cf_data);
-                clipboard_text.resize(length + 1);
+                g.ClipboardHandlerData.resize(length + 1);
-                CFDataGetBytes(cf_data, CFRangeMake(0, length), (UInt8*)clipboard_text.Data);
+                CFDataGetBytes(cf_data, CFRangeMake(0, length), (UInt8*)g.ClipboardHandlerData.Data);
-                clipboard_text[length] = 0;
+                g.ClipboardHandlerData[length] = 0;
                 CFRelease(cf_data);
-                return clipboard_text.Data;
+                return g.ClipboardHandlerData.Data;
             }
         }
     }
@@ -9906,17 +9908,17 @@ static const char* GetClipboardTextFn_DefaultImpl(void*)
 static const char* GetClipboardTextFn_DefaultImpl(void*)
 {
     ImGuiContext& g = *GImGui;
-    return g.PrivateClipboard.empty() ? NULL : g.PrivateClipboard.begin();
+    return g.ClipboardHandlerData.empty() ? NULL : g.ClipboardHandlerData.begin();
 }
 
 static void SetClipboardTextFn_DefaultImpl(void*, const char* text)
 {
     ImGuiContext& g = *GImGui;
-    g.PrivateClipboard.clear();
+    g.ClipboardHandlerData.clear();
     const char* text_end = text + strlen(text);
-    g.PrivateClipboard.resize((int)(text_end - text) + 1);
+    g.ClipboardHandlerData.resize((int)(text_end - text) + 1);
-    memcpy(&g.PrivateClipboard[0], text, (size_t)(text_end - text));
+    memcpy(&g.ClipboardHandlerData[0], text, (size_t)(text_end - text));
-    g.PrivateClipboard[(int)(text_end - text)] = 0;
+    g.ClipboardHandlerData[(int)(text_end - text)] = 0;
 }
 
 #endif

imgui_internal.h

@@ -1189,7 +1189,7 @@ struct ImGuiContext
     float                   DragSpeedDefaultRatio;              // If speed == 0.0f, uses (max-min) * DragSpeedDefaultRatio
     float                   ScrollbarClickDeltaToGrabCenter;    // Distance between mouse and center of grab box, normalized in parent space. Use storage?
     int                     TooltipOverrideCount;
-    ImVector<char>          PrivateClipboard;                   // If no custom clipboard handler is defined
+    ImVector<char>          ClipboardHandlerData;               // If no custom clipboard handler is defined
     ImVector<ImGuiID>       MenusIdSubmittedThisFrame;          // A list of menu IDs that were rendered at least once
 
     // Platform support