Merge branch 'mj/log-show-signature-conf'

"git log" learns log.showSignature configuration variable, and a
command line option "--no-show-signature" to countermand it.

* mj/log-show-signature-conf:
log: add log.showSignature configuration variable
log: add "--no-show-signature" command line option
t4202: refactor test

diff --combined Documentation/git-log.txt
index 4a6c47f843a8c0ca0b97a7b30648f7ca37e1f3c4,3995324024d49b2f79c3f53486d1c420f795e250..32246fdb007e9b25f414cff092b9bf0426c55d15
--- 1/Documentation/git-log.txt
--- 2/Documentation/git-log.txt
+++ b/Documentation/git-log.txt
@@@ -198,12 -198,16 +198,16 @@@ log.showRoot:
        `git log -p` output would be shown without a diff attached.
        The default is `true`.
  
+ log.showSignature::
+       If `true`, `git log` and related commands will act as if the
+       `--show-signature` option was passed to them.
+ 
  mailmap.*::
        See linkgit:git-shortlog[1].
  
  notes.displayRef::
        Which refs, in addition to the default set by `core.notesRef`
 -      or 'GIT_NOTES_REF', to read notes from when showing commit
 +      or `GIT_NOTES_REF`, to read notes from when showing commit
        messages with the `log` family of commands.  See
        linkgit:git-notes[1].
  +
@@@ -212,7 -216,7 +216,7 @@@ multiple times.  A warning will be issu
  but a glob that does not match any refs is silently ignored.
  +
  This setting can be disabled by the `--no-notes` option,
 -overridden by the 'GIT_NOTES_DISPLAY_REF' environment variable,
 +overridden by the `GIT_NOTES_DISPLAY_REF` environment variable,
  and overridden by the `--notes=<ref>` option.
  
  GIT

diff --combined builtin/log.c
index de47b4e89ae4d9aa1fbdd7187854d8fefc5ebe55,71032175052e41f18f2b184eed9caba306e3466f..0b6f7392b9fac31fe08f3e8743b44d018f6d4740
--- 1/builtin/log.c
--- 2/builtin/log.c
+++ b/builtin/log.c
@@@ -33,6 -33,7 +33,7 @@@ static const char *default_date_mode = 
  static int default_abbrev_commit;
  static int default_show_root = 1;
  static int default_follow;
+ static int default_show_signature;
  static int decoration_style;
  static int decoration_given;
  static int use_mailmap_config;
@@@ -119,6 -120,7 +120,7 @@@ static void cmd_log_init_defaults(struc
        rev->abbrev_commit = default_abbrev_commit;
        rev->show_root_diff = default_show_root;
        rev->subject_prefix = fmt_patch_subject_prefix;
+       rev->show_signature = default_show_signature;
        DIFF_OPT_SET(&rev->diffopt, ALLOW_TEXTCONV);
  
        if (default_date_mode)
@@@ -409,6 -411,10 +411,10 @@@ static int git_log_config(const char *v
                use_mailmap_config = git_config_bool(var, value);
                return 0;
        }
+       if (!strcmp(var, "log.showsignature")) {
+               default_show_signature = git_config_bool(var, value);
+               return 0;
+       }
  
        if (grep_config(var, value, cb) < 0)
                return -1;
@@@ -674,9 -680,9 +680,9 @@@ static int auto_number = 1
  
  static char *default_attach = NULL;
  
 -static struct string_list extra_hdr;
 -static struct string_list extra_to;
 -static struct string_list extra_cc;
 +static struct string_list extra_hdr = STRING_LIST_INIT_NODUP;
 +static struct string_list extra_to = STRING_LIST_INIT_NODUP;
 +static struct string_list extra_cc = STRING_LIST_INIT_NODUP;
  
  static void add_header(const char *value)
  {
@@@ -953,7 -959,7 +959,7 @@@ static void make_cover_letter(struct re
        struct pretty_print_context pp = {0};
        struct commit *head = list[0];
  
 -      if (rev->commit_format != CMIT_FMT_EMAIL)
 +      if (!cmit_fmt_is_mail(rev->commit_format))
                die(_("Cover letter needs email format"));
  
        committer = git_committer_info(0);

diff --combined revision.c
index 2f60062876237b4ac39b568af1a81294bf529793,3546ff9c1bcd64d8c0f2f1e67f4daae1c7ae240f..edba5b79bc1435483ee2555e1ba645743721ac5d
--- 1/revision.c
--- 2/revision.c
+++ b/revision.c
@@@ -1425,7 -1425,7 +1425,7 @@@ static void prepare_show_merge(struct r
                       ce_same_name(ce, active_cache[i+1]))
                        i++;
        }
 -      free_pathspec(&revs->prune_data);
 +      clear_pathspec(&revs->prune_data);
        parse_pathspec(&revs->prune_data, PATHSPEC_ALL_MAGIC & ~PATHSPEC_LITERAL,
                       PATHSPEC_PREFER_FULL | PATHSPEC_LITERAL_PATH, "", prune);
        revs->limited = 1;
@@@ -1871,6 -1871,8 +1871,8 @@@ static int handle_revision_opt(struct r
                revs->notes_opt.use_default_notes = 1;
        } else if (!strcmp(arg, "--show-signature")) {
                revs->show_signature = 1;
+       } else if (!strcmp(arg, "--no-show-signature")) {
+               revs->show_signature = 0;
        } else if (!strcmp(arg, "--show-linear-break") ||
                   starts_with(arg, "--show-linear-break=")) {
                if (starts_with(arg, "--show-linear-break="))