[PATCH] git-gui: do not use obsolete `git merge $msg HEAD $branch'

Use the modern `git merge' invocation pattern.

Since both `git merge' and `git fmt-merge-msg' obey the merge.log
configuration, instruct the former not to generate the log summary to
avoid that it appears twice in the commit message.

Signed-off-by: Johannes Sixt <redacted>
---
 lib/merge.tcl | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/lib/merge.tcl b/lib/merge.tcl
index 460d32f..f512456 100644
--- a/lib/merge.tcl
+++ b/lib/merge.tcl

@@ -115,8 +115,9 @@ method _start {} {
 	set cmd [list git]
 	lappend cmd merge
 	lappend cmd --strategy=recursive
+	lappend cmd --no-log
+	lappend cmd -m
 	lappend cmd [git fmt-merge-msg <[gitdir FETCH_HEAD]]
-	lappend cmd HEAD
 	lappend cmd $name
 
 	ui_status [mc "Merging %s and %s..." $current_branch $stitle]

-- 
2.6.2.337.ga235d84