InputText: Fixed not calling CallbackEdit on revert/clear with Escape key. (#8273) + rework comments.

Seems like there is no reason to not run that path. Amend ancient 9501cd99, f3ab5e625

docs/CHANGELOG.txt

@@ -62,6 +62,8 @@ Other changes:
   value is being modified. (#8242)
 - InputText: Added sanity check to detect some cases of passing a non
   zero-terminated input buffer.
+- InputText: Fixed not calling CallbackEdit on revert/clear with Escape key,
+  although IsItemEdited() was behaving correctly. (#8273)
 - Tables: Fixed TableAngledHeadersRow() creating an infinite horizontal
   scrolling region when the table is hosted in a viewport with negative
   coordinates.

imgui.h

@@ -1182,7 +1182,7 @@ enum ImGuiInputTextFlags_
     ImGuiInputTextFlags_CallbackAlways      = 1 << 20,  // Callback on each iteration. User code may query cursor position, modify text buffer.
     ImGuiInputTextFlags_CallbackCharFilter  = 1 << 21,  // Callback on character inputs to replace or discard them. Modify 'EventChar' to replace or discard, or return 1 in callback to discard.
     ImGuiInputTextFlags_CallbackResize      = 1 << 22,  // Callback on buffer capacity changes request (beyond 'buf_size' parameter value), allowing the string to grow. Notify when the string wants to be resized (for string types which hold a cache of their Size). You will be provided a new BufSize in the callback and NEED to honor it. (see misc/cpp/imgui_stdlib.h for an example of using this)
-    ImGuiInputTextFlags_CallbackEdit        = 1 << 23,  // Callback on any edit (note that InputText() already returns true on edit, the callback is useful mainly to manipulate the underlying buffer while focus is active)
+    ImGuiInputTextFlags_CallbackEdit        = 1 << 23,  // Callback on any edit. Note that InputText() already returns true on edit + you can always use IsItemEdited(). The callback is useful to manipulate the underlying buffer while focus is active.
 
     // Obsolete names
     //ImGuiInputTextFlags_AlwaysInsertMode  = ImGuiInputTextFlags_AlwaysOverwrite   // [renamed in 1.82] name was not matching behavior
@@ -2442,7 +2442,7 @@ struct ImGuiIO
 // Shared state of InputText(), passed as an argument to your callback when a ImGuiInputTextFlags_Callback* flag is used.
 // The callback function should return 0 by default.
 // Callbacks (follow a flag name and see comments in ImGuiInputTextFlags_ declarations for more details)
-// - ImGuiInputTextFlags_CallbackEdit:        Callback on buffer edit (note that InputText() already returns true on edit, the callback is useful mainly to manipulate the underlying buffer while focus is active)
+// - ImGuiInputTextFlags_CallbackEdit:        Callback on buffer edit. Note that InputText() already returns true on edit + you can always use IsItemEdited(). The callback is useful to manipulate the underlying buffer while focus is active.
 // - ImGuiInputTextFlags_CallbackAlways:      Callback on each iteration
 // - ImGuiInputTextFlags_CallbackCompletion:  Callback on pressing TAB
 // - ImGuiInputTextFlags_CallbackHistory:     Callback on pressing Up/Down arrows

imgui_widgets.cpp

@@ -4977,19 +4977,17 @@ bool ImGui::InputTextEx(const char* label, const char* hint, char* buf, int buf_
             }
         }
 
-        // 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
+        // FIXME-OPT: We always reapply the live buffer back to the input buffer before clearing ActiveId,
+        // even though strictly speaking it wasn't modified on this frame. Should mark dirty state from the stb_textedit callbacks.
+        // If we do that, need to ensure that as special case, 'validated == true' also writes back.
+        // This also allows the user to use InputText() 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).
-        const bool apply_edit_back_to_user_buffer = !revert_edit || (validated && (flags & ImGuiInputTextFlags_EnterReturnsTrue) != 0);
+        const bool apply_edit_back_to_user_buffer = true;// !revert_edit || (validated && (flags & ImGuiInputTextFlags_EnterReturnsTrue) != 0);
         if (apply_edit_back_to_user_buffer)
         {
-            // Apply new value immediately - copy modified buffer back
+            // Apply current edited text immediately.
             // 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.
 
             // User callback
             if ((flags & (ImGuiInputTextFlags_CallbackCompletion | ImGuiInputTextFlags_CallbackHistory | ImGuiInputTextFlags_CallbackEdit | ImGuiInputTextFlags_CallbackAlways)) != 0)