patch 8.2.5126: substitute may overrun destination buffer
Problem: Substitute may overrun destination buffer.
Solution: Disallow switching buffers in a substitute expression.
diff --git a/src/testdir/test_substitute.vim b/src/testdir/test_substitute.vim
index 46ea955..c056fa9 100644
--- a/src/testdir/test_substitute.vim
+++ b/src/testdir/test_substitute.vim
@@ -1063,6 +1063,19 @@
call delete('Xresult')
endfunc
+" This was editing a script file from the expression
+func Test_sub_edit_scriptfile()
+ new
+ norm o0000000000000000000000000000000000000000000000000000
+ func EditScript()
+ silent! scr! Xfile
+ endfunc
+ s/\%')/\=EditScript()
+
+ delfunc EditScript
+ bwipe!
+endfunc
+
" Test for the 2-letter and 3-letter :substitute commands
func Test_substitute_short_cmd()
new