2.5 Bugfixes

#19302: the spin operator did not redo correct when changing properties.
Actually the problem was somewhere else, the search menu always did an
unnecessary undo push, which conflicted with an operator undo push with
the same name. Only in the case of "Spin" was this noticed, because it's
name is so short and you actually type it completely.
#19328: swapping areas could crash when dragging mouse outside the window.

Attempted fix for #19331, #19335 as well, where backspace and some other
keys give square characters instead of working as expected. Couldn't
reproducable here, so please test.

source/blender/editors/interface/interface.c

@@ -2264,6 +2264,9 @@ static uiBut *ui_def_but(uiBlock *block, int type, int retval, char *str, short
 		}
 	}
 
+	if(!ELEM7(but->type, BLOCK, BUT, LABEL, PULLDOWN, ROUNDBOX, LISTBOX, SEARCH_MENU))
+		but->flag |= UI_BUT_UNDO;
+
 	BLI_addtail(&block->buttons, but);
 	
 	if(block->curlayout)