InputText: Fix handling of paste failure (buffer full) which in some cases could corrupt the undo stack. (#4038)

docs/CHANGELOG.txt

@@ -121,6 +121,8 @@ Other Changes:
   consistent with the compile-time default. (#3922)
 - DragScalar: Add default value for v_speed argument to match higher-level functions. (#3922) [@eliasdaler]
 - ColorEdit4: Alpha default to 255 (instead of 0) when omitted in hex input. (#3973) [@squadack]
+- InputText: Fix handling of paste failure (buffer full) which in some cases could corrupt the undo stack. (#4038)
+  (fix submitted to https://github.com/nothings/stb/pull/1158) [@Unit2Ed, @ocornut]
 - InputText: Do not filter private unicode codepoints (e.g. icons) when pasted from clipboard. (#4005) [@dougbinks]
 - InputText: Align caret/cursor to pixel coordinates. (#4080) [@elvissteinjr]
 - InputText: Fixed CTRL+Arrow or OSX double-click leaking the presence of spaces when ImGuiInputTextFlags_Password

imstb_textedit.h

@@ -716,9 +716,11 @@ static int stb_textedit_paste_internal(STB_TEXTEDIT_STRING *str, STB_TexteditSta
       state->has_preferred_x = 0;
       return 1;
    }
-   // remove the undo since we didn't actually insert the characters
-   if (state->undostate.undo_point)
-      --state->undostate.undo_point;
+   // [DEAR IMGUI]
+   //// remove the undo since we didn't actually insert the characters
+   //if (state->undostate.undo_point)
+   //   --state->undostate.undo_point;
+   // note: paste failure will leave deleted selection, may be restored with an undo (see https://github.com/nothings/stb/issues/734 for details)
    return 0;
 }