Merge branch 'rj/format-patch-auto-cover-with-interdiff'

"git format-patch --interdiff" for multi-patch series learned to
turn on cover letters automatically (unless told never to enable
cover letter with "--no-cover-letter" and such).

* rj/format-patch-auto-cover-with-interdiff:
  format-patch: assume --cover-letter for diff in multi-patch series
  t4014: cleanups in a few tests

diff --cc builtin/log.c
index b8846a945829e34c752a86f0b56608652543d985,d61cdbf304df168d2f706edba0b11e245f69f529..21a81c72ac76be6cbf3ad824ef425c855840bdce
--- 1/builtin/log.c
--- 2/builtin/log.c
+++ b/builtin/log.c
@@@ -2380,14 -2253,16 +2380,16 @@@ int cmd_format_patch(int argc, const ch
                goto done;
        total = nr;
        if (cover_letter == -1) {
 -              if (config_cover_letter == COVER_AUTO)
 +              if (cfg.config_cover_letter == COVER_AUTO)
                        cover_letter = (total > 1);
 -                      cover_letter = (config_cover_letter != COVER_OFF);
+               else if ((idiff_prev.nr || rdiff_prev) && (total > 1))
++                      cover_letter = (cfg.config_cover_letter != COVER_OFF);
                else
 -                      cover_letter = (config_cover_letter == COVER_ON);
 +                      cover_letter = (cfg.config_cover_letter == COVER_ON);
        }
 -      if (!keep_subject && auto_number && (total > 1 || cover_letter))
 -              numbered = 1;
 -      if (numbered)
 +      if (!cfg.keep_subject && cfg.auto_number && (total > 1 || cover_letter))
 +              cfg.numbered = 1;
 +      if (cfg.numbered)
                rev.total = total + start_number - 1;
  
        if (idiff_prev.nr) {

diff --cc t/t4014-format-patch.sh
Simple merge