patch 9.0.2031: TextChangedI may be triggered by non-insert mode change

Problem:  `TextChangedI` can trigger on entering Insert mode if there
          was previously a change not in Insert mode.
Solution: Make it trigger only when text is actually changed in Insert
          mode.

closes: #13265
closes: #13338

Signed-off-by: Christian Brabandt <cb@256bit.org>
Co-authored-by: Evgeni Chasnovski <evgeni.chasnovski@gmail.com>
diff --git a/src/edit.c b/src/edit.c
index a515425..014d1c7 100644
--- a/src/edit.c
+++ b/src/edit.c
@@ -174,6 +174,9 @@
 	return FALSE;
     }
     ins_compl_clear();	    // clear stuff for CTRL-X mode
+    // Reset Changedtick_i, so that TextChangedI will only be triggered for stuff
+    // from insert mode
+    curbuf->b_last_changedtick_i = CHANGEDTICK(curbuf);
 
     /*
      * Trigger InsertEnter autocommands.  Do not do this for "r<CR>" or "grx".
@@ -840,6 +843,7 @@
 		if (cmdchar != 'r' && cmdchar != 'v' && c != Ctrl_C)
 		    ins_apply_autocmds(EVENT_INSERTLEAVE);
 		did_cursorhold = FALSE;
+		curbuf->b_last_changedtick = CHANGEDTICK(curbuf);
 		return (c == Ctrl_O);
 	    }
 	    continue;