commit 1814183b865059679f6ee526ec23fc575e536e66
author Bram Moolenaar <Bram@vim.org> Sun Jun 25 21:17:25 2017 +0200
committer Bram Moolenaar <Bram@vim.org> Sun Jun 25 21:17:25 2017 +0200
tree 27687232ab6376a33759072132c4e3bf9c20ba17
parent 182a17b1e80b92826204d967808df0d30eb2ef27

patch 8.0.0677: setting 'filetype' may switch buffers

Problem:    Setting 'filetype' internally may cause the current buffer and
            window to change unexpectedly.
Solution:   Set curbuf_lock. (closes #1734)

src/ex_cmds.c

diff --git a/src/ex_cmds.c b/src/ex_cmds.c
index bb9a927..39f658a 100644
--- a/src/ex_cmds.c
+++ b/src/ex_cmds.c
@@ -6835,7 +6835,11 @@
 #ifdef FEAT_AUTOCMD
     /* Set filetype to "help" if still needed. */
     if (STRCMP(curbuf->b_p_ft, "help") != 0)
+    {
+	++curbuf_lock;
 	set_option_value((char_u *)"ft", 0L, (char_u *)"help", OPT_LOCAL);
+	--curbuf_lock;
+    }
 #endif
 
 #ifdef FEAT_SYN_HL