Merge branch 'gs/rebase-allow-empty-message'

"git rebase" learned to take "--allow-empty-message" option.

* gs/rebase-allow-empty-message:
rebase: add --allow-empty-message option

diff --combined builtin/rebase--helper.c
index 00faf14d07403fedd07bfbbaf1123bea07e3e328,2090114e9a33cfd7cf289b43883cbad4b984d8bb..ad074705bb51d1de4221b3c5dfaa7229903c0ef0
--- 1/builtin/rebase--helper.c
--- 2/builtin/rebase--helper.c
+++ b/builtin/rebase--helper.c
@@@ -22,6 -22,8 +22,8 @@@ int cmd_rebase__helper(int argc, const 
        struct option options[] = {
                OPT_BOOL(0, "ff", &opts.allow_ff, N_("allow fast-forward")),
                OPT_BOOL(0, "keep-empty", &keep_empty, N_("keep empty commits")),
+               OPT_BOOL(0, "allow-empty-message", &opts.allow_empty_message,
+                       N_("allow commits with empty messages")),
                OPT_CMDMODE(0, "continue", &command, N_("continue rebase"),
                                CONTINUE),
                OPT_CMDMODE(0, "abort", &command, N_("abort rebase"),
@@@ -43,7 -45,7 +45,7 @@@
                OPT_END()
        };
  
 -      git_config(git_default_config, NULL);
 +      sequencer_init_config(&opts);
        git_config_get_bool("rebase.abbreviatecommands", &abbreviate_commands);
  
        opts.action = REPLAY_INTERACTIVE_REBASE;