format-patch: make zero-length subject prefixes prettier

If you give a zero-length subject prefix to format-patch
(e.g., "format-patch --subject-prefix="), we will print the
ugly:

  Subject: [ 1/2] your subject here

because we always insert a space between the prefix and
numbering. Requiring the user to provide the space in their
prefix would be more flexible, but would break existing
usage. This patch provides a DWIM and suppresses the space
for zero-length prefixes, under the assumption that nobody
actually wants "[ 1/2]".

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

diff --git a/log-tree.c b/log-tree.c
index 2a1e3a94c910cd74e41303d8b7aefa539817c831..296f417dfcc2fe966527064aa4a95dc96a8eca2d 100644 (file)
--- a/log-tree.c
+++ b/log-tree.c
@@ -294,8 +294,9 @@ void log_write_email_headers(struct rev_info *opt, struct commit *commit,
        if (opt->total > 0) {
                static char buffer[64];
                snprintf(buffer, sizeof(buffer),
-                        "Subject: [%s %0*d/%d] ",
+                        "Subject: [%s%s%0*d/%d] ",
                         opt->subject_prefix,
+                        *opt->subject_prefix ? " " : "",
                         digits_in_number(opt->total),
                         opt->nr, opt->total);
                subject = buffer;

diff --git a/t/t4014-format-patch.sh b/t/t4014-format-patch.sh
index 045cee312cdeb515869eeeda3f7b167fb5b91504..92248d24c48a65ab89a5b0ad255357f6034e6ad4 100755 (executable)
--- a/t/t4014-format-patch.sh
+++ b/t/t4014-format-patch.sh
@@ -851,4 +851,22 @@ test_expect_success 'subject lines do not have 822 atom-quoting' '
        test_cmp expect actual
 '
 
+cat >expect <<'EOF'
+Subject: [PREFIX 1/1] header with . in it
+EOF
+test_expect_success 'subject prefixes have space prepended' '
+       git format-patch -n -1 --stdout --subject-prefix=PREFIX >patch &&
+       grep ^Subject: patch >actual &&
+       test_cmp expect actual
+'
+
+cat >expect <<'EOF'
+Subject: [1/1] header with . in it
+EOF
+test_expect_success 'empty subject prefix does not have extra space' '
+       git format-patch -n -1 --stdout --subject-prefix= >patch &&
+       grep ^Subject: patch >actual &&
+       test_cmp expect actual
+'
+
 test_done