From 9bd205a527d28deebed8302f6d93882fcb6b6c04 Mon Sep 17 00:00:00 2001
From: Quantum <quantum2048@gmail.com>
Date: Thu, 19 Aug 2021 15:57:20 -0400
Subject: [PATCH] [client] imgui: fix modifier key modification race

imgui really hates it when we update the modifier key state after igNewFrame.
The result is:

    void ImGui::ErrorCheckEndFrameSanityChecks(): Assertion
    `(key_mod_flags == 0 || g.IO.KeyMods == key_mod_flags) &&
    "Mismatching io.KeyCtrl/io.KeyShift/io.KeyAlt/io.KeySuper vs io.KeyMods"'
    failed.

Therefore, we buffer the modifier state information and update it in the IO
object right before we call igNewFrame.
---
 client/src/app.c  | 13 +++++++++----
 client/src/main.h |  4 ++++
 2 files changed, 13 insertions(+), 4 deletions(-)

diff --git a/client/src/app.c b/client/src/app.c
index 416433ef..58d9e304 100644
--- a/client/src/app.c
+++ b/client/src/app.c
@@ -406,10 +406,10 @@ void app_handleKeyboardTyped(const char * typed)
 
 void app_handleKeyboardModifiers(bool ctrl, bool shift, bool alt, bool super)
 {
-  g_state.io->KeyCtrl  = ctrl;
-  g_state.io->KeyShift = shift;
-  g_state.io->KeyAlt   = alt;
-  g_state.io->KeySuper = super;
+  g_state.modCtrl  = ctrl;
+  g_state.modShift = shift;
+  g_state.modAlt   = alt;
+  g_state.modSuper = super;
 }
 
 void app_handleKeyboardLEDs(bool numLock, bool capsLock, bool scrollLock)
@@ -806,6 +806,11 @@ int app_renderOverlay(struct Rect * rects, int maxRects)
   struct Overlay * overlay;
   struct Rect buffer[MAX_OVERLAY_RECTS];
 
+  g_state.io->KeyCtrl  = g_state.modCtrl;
+  g_state.io->KeyShift = g_state.modShift;
+  g_state.io->KeyAlt   = g_state.modAlt;
+  g_state.io->KeySuper = g_state.modSuper;
+
   igNewFrame();
 
   if (g_state.overlayInput)
diff --git a/client/src/main.h b/client/src/main.h
index 1457a1d2..b75c65c3 100644
--- a/client/src/main.h
+++ b/client/src/main.h
@@ -56,6 +56,10 @@ struct AppState
   bool             overlayInput;
   ImGuiMouseCursor cursorLast;
   char           * imGuiIni;
+  bool             modCtrl;
+  bool             modShift;
+  bool             modAlt;
+  bool             modSuper;
 
   bool        alertShow;
   char      * alertMessage;