InputText: Fixed a one-frame display glitch where pressing Escape to revert after a deletion would lead to small garbage being displayed for one frame. (#3008)

Curiously very old, amend 83efdce and bdbb2b2. Using stb_ functions updated ->CurLenA without updating ->TextA, leading to `buf_display_end = buf_display + state->CurLenA;` in the display.
Since f3ab5e6 they are 1 case out of 4 which didn't apply back to ->TextA and this is essentially the one where we ensure appliance. Another solution would be to alter the lower display code, but applying to TextA makes things more consistent.

Author: ocornut

docs/CHANGELOG.txt

@@ -83,6 +83,8 @@ Other Changes:
   return value is overriden by focus when gamepad/keyboard navigation is active.
 - InputText: Fixed pressing Tab emitting two tabs characters because of dual Keys/Chars events being
   trickled with the new input queue (happened on some backends only). (#2467, #1336)
+- InputText: Fixed a one-frame display glitch where pressing Escape to revert after a deletion
+  would lead to small garbage being displayed for one frame. Curiously a rather old bug! (#3008)
 - Tables: Fixed incorrect border height used for logic when resizing one of several synchronized
   instance of a same table ID, when instances have a different height. (#3955).
 - Tables: Fixed incorrect auto-fit of parent windows when using non-resizable weighted columns. (#5276)

imgui.h

@@ -65,7 +65,7 @@ Index of this file:
 // Version
 // (Integer encoded as XYYZZ for use in #if preprocessor conditionals. Work in progress versions typically starts at XYY99 then bounce up to XYY00, XYY01 etc. when release tagging happens)
 #define IMGUI_VERSION               "1.88 WIP"
-#define IMGUI_VERSION_NUM           18723
+#define IMGUI_VERSION_NUM           18724
 #define IMGUI_CHECKVERSION()        ImGui::DebugCheckVersionAndDataLayout(IMGUI_VERSION, sizeof(ImGuiIO), sizeof(ImGuiStyle), sizeof(ImVec2), sizeof(ImVec4), sizeof(ImDrawVert), sizeof(ImDrawIdx))
 #define IMGUI_HAS_TABLE
 

imgui_widgets.cpp

@@ -4425,22 +4425,24 @@ bool ImGui::InputTextEx(const char* label, const char* hint, char* buf, int buf_
             }
         }
 
+        // Apply ASCII value
+        if (!is_readonly)
+        {
+            state->TextAIsValid = true;
+            state->TextA.resize(state->TextW.Size * 4 + 1);
+            ImTextStrToUtf8(state->TextA.Data, state->TextA.Size, state->TextW.Data, NULL);
+        }
+
         // When using 'ImGuiInputTextFlags_EnterReturnsTrue' as a special case we reapply the live buffer back to the input buffer before clearing ActiveId, even though strictly speaking it wasn't modified on this frame.
         // If we didn't do that, code like InputInt() with ImGuiInputTextFlags_EnterReturnsTrue would fail.
         // This also allows the user to use InputText() with ImGuiInputTextFlags_EnterReturnsTrue without maintaining any user-side storage (please note that if you use this property along ImGuiInputTextFlags_CallbackResize you can end up with your temporary string object unnecessarily allocating once a frame, either store your string data, either if you don't then don't use ImGuiInputTextFlags_CallbackResize).
-        bool apply_edit_back_to_user_buffer = !cancel_edit || (enter_pressed && (flags & ImGuiInputTextFlags_EnterReturnsTrue) != 0);
+        const bool apply_edit_back_to_user_buffer = !cancel_edit || (enter_pressed && (flags & ImGuiInputTextFlags_EnterReturnsTrue) != 0);
         if (apply_edit_back_to_user_buffer)
         {
             // Apply new value immediately - copy modified buffer back
             // Note that as soon as the input box is active, the in-widget value gets priority over any underlying modification of the input buffer
             // FIXME: We actually always render 'buf' when calling DrawList->AddText, making the comment above incorrect.
             // FIXME-OPT: CPU waste to do this every time the widget is active, should mark dirty state from the stb_textedit callbacks.
-            if (!is_readonly)
-            {
-                state->TextAIsValid = true;
-                state->TextA.resize(state->TextW.Size * 4 + 1);
-                ImTextStrToUtf8(state->TextA.Data, state->TextA.Size, state->TextW.Data, NULL);
-            }
 
             // User callback
             if ((flags & (ImGuiInputTextFlags_CallbackCompletion | ImGuiInputTextFlags_CallbackHistory | ImGuiInputTextFlags_CallbackEdit | ImGuiInputTextFlags_CallbackAlways)) != 0)