cat-file: add mailmap subcommand to --batch-command

git-cat-file(1)'s --batch-command works with the --use-mailmap option,
but this option needs to be set when the process is created. This means
we cannot change this option mid-operation.

At GitLab, Gitaly keeps interacting with a long-lived git-cat-file
process and it would be useful if --batch-command supported toggling
mailmap dynamically on an existing process.

Add a `mailmap` subcommand to --batch-command that takes a boolean
argument (usual ways you can specify a boolean value like 'yes', 'true',
etc., are supported). Mailmap data is loaded lazily and kept in memory,
while a helper centralizes the one-time load path used both at startup
and from the batch-command handler.

Extend tests to cover runtime toggling, startup option interactions
(`--mailmap`/`--no-mailmap`), accepted boolean forms, and invalid values.

Signed-off-by: Siddharth Asthana <siddharthasthana31@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

diff --git a/Documentation/git-cat-file.adoc b/Documentation/git-cat-file.adoc
index c139f55a168d61fa0db8ef713c55d84468c9dc9d..86b9181599317ec5fd6c4d8ef24079f29ad168ab 100644 (file)
--- a/Documentation/git-cat-file.adoc
+++ b/Documentation/git-cat-file.adoc
@@ -174,6 +174,11 @@ flush::
        since the beginning or since the last flush was issued. When `--buffer`
        is used, no output will come until a `flush` is issued. When `--buffer`
        is not used, commands are flushed each time without issuing `flush`.
+
+`mailmap (<bool>)`::
+       Enable or disable mailmap for subsequent commands. The `<bool>`
+       argument accepts the same boolean values as linkgit:git-config[1].
+       The mailmap data is read upon the first use and only once.
 --
 +
 

diff --git a/builtin/cat-file.c b/builtin/cat-file.c
index b6f12f41d6070a9733588d8f2f258a65c5903da7..631e19a4fbf4ca1740336b59d8c6442bf4a70195 100644 (file)
--- a/builtin/cat-file.c
+++ b/builtin/cat-file.c
@@ -57,6 +57,20 @@ static int use_mailmap;
 
 static char *replace_idents_using_mailmap(char *, size_t *);
 
+/*
+ * The mailmap is initialized with .strdup_strings set to 0,
+ * but read_mailmap() sets the bit to 1 (this is true even when
+ * not a single mailmap entry is read), so it can be used for
+ * lazy loading.
+ */
+static void load_mailmap(void)
+{
+       if (mailmap.strdup_strings)
+               return;
+
+       read_mailmap(the_repository, &mailmap);
+}
+
 static char *replace_idents_using_mailmap(char *object_buf, size_t *size)
 {
        struct strbuf sb = STRBUF_INIT;
@@ -692,6 +706,20 @@ static void parse_cmd_info(struct batch_options *opt,
        batch_one_object(line, output, opt, data);
 }
 
+static void parse_cmd_mailmap(struct batch_options *opt UNUSED,
+                             const char *line,
+                             struct strbuf *output UNUSED,
+                             struct expand_data *data UNUSED)
+{
+       use_mailmap = git_parse_maybe_bool(line);
+
+       if (use_mailmap < 0)
+               die(_("mailmap: invalid boolean '%s'"), line);
+
+       if (use_mailmap)
+               load_mailmap();
+}
+
 static void dispatch_calls(struct batch_options *opt,
                struct strbuf *output,
                struct expand_data *data,
@@ -725,9 +753,10 @@ static const struct parse_cmd {
        parse_cmd_fn_t fn;
        unsigned takes_args;
 } commands[] = {
-       { "contents", parse_cmd_contents, 1},
-       { "info", parse_cmd_info, 1},
-       { "flush", NULL, 0},
+       { "contents", parse_cmd_contents, 1 },
+       { "info", parse_cmd_info, 1 },
+       { "flush", NULL, 0 },
+       { "mailmap", parse_cmd_mailmap, 1 },
 };
 
 static void batch_objects_command(struct batch_options *opt,
@@ -1128,7 +1157,7 @@ int cmd_cat_file(int argc,
        opt_epts = (opt == 'e' || opt == 'p' || opt == 't' || opt == 's');
 
        if (use_mailmap)
-               read_mailmap(the_repository, &mailmap);
+               load_mailmap();
 
        switch (batch.objects_filter.choice) {
        case LOFC_DISABLED:

diff --git a/t/t4203-mailmap.sh b/t/t4203-mailmap.sh
index 74b7ddccb26d59fab468ef65849c580e142f25c0..249548eb9bc15901ec7effecae6f31f9f3b8185e 100755 (executable)
--- a/t/t4203-mailmap.sh
+++ b/t/t4203-mailmap.sh
@@ -1133,6 +1133,111 @@ test_expect_success 'git cat-file --batch-command returns correct size with --us
        test_cmp expect actual
 '
 
+test_expect_success 'git cat-file --batch-command mailmap yes enables mailmap mid-stream' '
+       test_when_finished "rm .mailmap" &&
+       cat >.mailmap <<-\EOF &&
+       C O Mitter <committer@example.com> Orig <orig@example.com>
+       EOF
+       commit_sha=$(git rev-parse HEAD) &&
+       git cat-file commit HEAD >commit_no_mailmap.out &&
+       git cat-file --use-mailmap commit HEAD >commit_mailmap.out &&
+       size_no_mailmap=$(wc -c <commit_no_mailmap.out) &&
+       size_mailmap=$(wc -c <commit_mailmap.out) &&
+       printf "info HEAD\nmailmap yes\ninfo HEAD\n" | git cat-file --batch-command >actual &&
+       echo $commit_sha commit $size_no_mailmap >expect &&
+       echo $commit_sha commit $size_mailmap >>expect &&
+       test_cmp expect actual
+'
+
+test_expect_success 'git cat-file --batch-command mailmap no disables mailmap mid-stream' '
+       test_when_finished "rm .mailmap" &&
+       cat >.mailmap <<-\EOF &&
+       C O Mitter <committer@example.com> Orig <orig@example.com>
+       EOF
+       commit_sha=$(git rev-parse HEAD) &&
+       git cat-file commit HEAD >commit_no_mailmap.out &&
+       git cat-file --use-mailmap commit HEAD >commit_mailmap.out &&
+       size_no_mailmap=$(wc -c <commit_no_mailmap.out) &&
+       size_mailmap=$(wc -c <commit_mailmap.out) &&
+       printf "mailmap yes\ninfo HEAD\nmailmap no\ninfo HEAD\n" | git cat-file --batch-command >actual &&
+       echo $commit_sha commit $size_mailmap >expect &&
+       echo $commit_sha commit $size_no_mailmap >>expect &&
+       test_cmp expect actual
+'
+
+test_expect_success 'git cat-file --batch-command mailmap works in --buffer mode' '
+       test_when_finished "rm .mailmap" &&
+       cat >.mailmap <<-\EOF &&
+       C O Mitter <committer@example.com> Orig <orig@example.com>
+       EOF
+       commit_sha=$(git rev-parse HEAD) &&
+       git cat-file commit HEAD >commit_no_mailmap.out &&
+       git cat-file --use-mailmap commit HEAD >commit_mailmap.out &&
+       size_no_mailmap=$(wc -c <commit_no_mailmap.out) &&
+       size_mailmap=$(wc -c <commit_mailmap.out) &&
+       printf "mailmap yes\ninfo HEAD\nmailmap no\ninfo HEAD\nflush\n" | git cat-file --batch-command --buffer >actual &&
+       echo $commit_sha commit $size_mailmap >expect &&
+       echo $commit_sha commit $size_no_mailmap >>expect &&
+       test_cmp expect actual
+'
+
+test_expect_success 'git cat-file --batch-command mailmap no overrides startup --mailmap' '
+       test_when_finished "rm .mailmap" &&
+       cat >.mailmap <<-\EOF &&
+       C O Mitter <committer@example.com> Orig <orig@example.com>
+       EOF
+       commit_sha=$(git rev-parse HEAD) &&
+       git cat-file --use-mailmap commit HEAD >commit_mailmap.out &&
+       size_mailmap=$(wc -c <commit_mailmap.out) &&
+       git cat-file commit HEAD >commit_no_mailmap.out &&
+       size_no_mailmap=$(wc -c <commit_no_mailmap.out) &&
+       printf "info HEAD\nmailmap no\ninfo HEAD\n" | \
+               git cat-file --mailmap --batch-command >actual &&
+       echo $commit_sha commit $size_mailmap >expect &&
+       echo $commit_sha commit $size_no_mailmap >>expect &&
+       test_cmp expect actual
+'
+
+test_expect_success 'git cat-file --batch-command mailmap yes overrides startup --no-mailmap' '
+       test_when_finished "rm .mailmap" &&
+       cat >.mailmap <<-\EOF &&
+       C O Mitter <committer@example.com> Orig <orig@example.com>
+       EOF
+       commit_sha=$(git rev-parse HEAD) &&
+       git cat-file commit HEAD >commit_no_mailmap.out &&
+       size_no_mailmap=$(wc -c <commit_no_mailmap.out) &&
+       git cat-file --use-mailmap commit HEAD >commit_mailmap.out &&
+       size_mailmap=$(wc -c <commit_mailmap.out) &&
+       printf "info HEAD\nmailmap yes\ninfo HEAD\n" | \
+               git cat-file --no-mailmap --batch-command >actual &&
+       echo $commit_sha commit $size_no_mailmap >expect &&
+       echo $commit_sha commit $size_mailmap >>expect &&
+       test_cmp expect actual
+'
+
+test_expect_success 'git cat-file --batch-command mailmap accepts true/false' '
+       test_when_finished "rm .mailmap" &&
+       cat >.mailmap <<-\EOF &&
+       C O Mitter <committer@example.com> Orig <orig@example.com>
+       EOF
+       commit_sha=$(git rev-parse HEAD) &&
+       git cat-file commit HEAD >commit_no_mailmap.out &&
+       size_no_mailmap=$(wc -c <commit_no_mailmap.out) &&
+       git cat-file --use-mailmap commit HEAD >commit_mailmap.out &&
+       size_mailmap=$(wc -c <commit_mailmap.out) &&
+       printf "mailmap true\ninfo HEAD\nmailmap false\ninfo HEAD\n" | \
+               git cat-file --batch-command >actual &&
+       echo $commit_sha commit $size_mailmap >expect &&
+       echo $commit_sha commit $size_no_mailmap >>expect &&
+       test_cmp expect actual
+'
+
+test_expect_success 'git cat-file --batch-command mailmap rejects invalid boolean' '
+       echo "mailmap maybe" >in &&
+       test_must_fail git cat-file --batch-command <in 2>err &&
+       test_grep "mailmap: invalid boolean .*maybe" err
+'
+
 test_expect_success 'git cat-file --mailmap works with different author and committer' '
        test_when_finished "rm .mailmap" &&
        cat >.mailmap <<-\EOF &&