When callers are using `cat-file` via one of the stdin-driven `--batch`
modes, all input is newline-delimited. This presents a problem when
callers wish to ask about, e.g. tree-entries that have a newline
character present in their filename.
To support this niche scenario, introduce a new `-z` mode to the
`--batch`, `--batch-check`, and `--batch-command` suite of options that
instructs `cat-file` to treat its input as NUL-delimited, allowing the
individual commands themselves to have newlines present.
The refactoring here is slightly unfortunate, since we turn loops like:
while (strbuf_getline(&buf, stdin) != EOF)
into:
while (1) {
int ret;
if (opt->nul_terminated)
ret = strbuf_getline_nul(&input, stdin);
else
ret = strbuf_getline(&input, stdin);
if (ret == EOF)
break;
}
It's tempting to think that we could use `strbuf_getwholeline()` and
specify either `\n` or `\0` as the terminating character. But for input
on platforms that include a CR character preceeding the LF, this
wouldn't quite be the same, since `strbuf_getline(...)` will trim any
trailing CR, while `strbuf_getwholeline(&buf, stdin, '\n')` will not.
In the future, we could clean this up further by introducing a variant
of `strbuf_getwholeline()` that addresses the aforementioned gap, but
that approach felt too heavy-handed for this pair of uses.
Some tests are added in t1006 to ensure that `cat-file` produces the
same output in `--batch`, `--batch-check`, and `--batch-command` modes
with and without the new `-z` option.
Signed-off-by: Taylor Blau <me@xxxxxxxxxxxx>
---
Documentation/git-cat-file.txt | 7 +++++-
builtin/cat-file.c | 28 ++++++++++++++++++++---
t/t1006-cat-file.sh | 42 +++++++++++++++++++++++++++++++++-
3 files changed, 72 insertions(+), 5 deletions(-)
diff --git a/Documentation/git-cat-file.txt b/Documentation/git-cat-file.txt
index 24a811f0ef..3515350ed6 100644
--- a/Documentation/git-cat-file.txt
+++ b/Documentation/git-cat-file.txt
@@ -14,7 +14,7 @@ SYNOPSIS
'git cat-file' (-t | -s) [--allow-unknown-type] <object>
'git cat-file' (--batch | --batch-check | --batch-command) [--batch-all-objects]
[--buffer] [--follow-symlinks] [--unordered]
- [--textconv | --filters]
+ [--textconv | --filters] [-z]
'git cat-file' (--textconv | --filters)
[<rev>:<path|tree-ish> | --path=<path|tree-ish> <rev>]
@@ -207,6 +207,11 @@ respectively print:
/etc/passwd
--
+-z::
+ Only meaningful with `--batch`, `--batch-check`, or
+ `--batch-command`; input is NUL-delimited instead of
+ newline-delimited.
+
OUTPUT
------
diff --git a/builtin/cat-file.c b/builtin/cat-file.c
index f42782e955..c3602d15df 100644
--- a/builtin/cat-file.c
+++ b/builtin/cat-file.c
@@ -31,6 +31,7 @@ struct batch_options {
int all_objects;
int unordered;
int transform_mode; /* may be 'w' or 'c' for --filters or --textconv */
+ int nul_terminated;
const char *format;
};
@@ -614,12 +615,20 @@ static void batch_objects_command(struct batch_options *opt,
struct queued_cmd *queued_cmd = NULL;
size_t alloc = 0, nr = 0;
- while (!strbuf_getline(&input, stdin)) {
- int i;
+ while (1) {
+ int i, ret;
const struct parse_cmd *cmd = NULL;
const char *p = NULL, *cmd_end;
struct queued_cmd call = {0};
+ if (opt->nul_terminated)
+ ret = strbuf_getline_nul(&input, stdin);
+ else
+ ret = strbuf_getline(&input, stdin);
+
+ if (ret)
+ break;
+
if (!input.len)
die(_("empty command in input"));
if (isspace(*input.buf))
@@ -763,7 +772,16 @@ static int batch_objects(struct batch_options *opt)
goto cleanup;
}
- while (strbuf_getline(&input, stdin) != EOF) {
+ while (1) {
+ int ret;
+ if (opt->nul_terminated)
+ ret = strbuf_getline_nul(&input, stdin);
+ else
+ ret = strbuf_getline(&input, stdin);
+
+ if (ret == EOF)
+ break;
+
if (data.split_on_whitespace) {
/*
* Split at first whitespace, tying off the beginning
@@ -866,6 +884,7 @@ int cmd_cat_file(int argc, const char **argv, const char *prefix)
N_("like --batch, but don't emit <contents>"),
PARSE_OPT_OPTARG | PARSE_OPT_NONEG,
batch_option_callback),
+ OPT_BOOL('z', NULL, &batch.nul_terminated, N_("stdin is NUL-terminated")),
OPT_CALLBACK_F(0, "batch-command", &batch, N_("format"),
N_("read commands from stdin"),
PARSE_OPT_OPTARG | PARSE_OPT_NONEG,
@@ -921,6 +940,9 @@ int cmd_cat_file(int argc, const char **argv, const char *prefix)
else if (batch.all_objects)
usage_msg_optf(_("'%s' requires a batch mode"), usage, options,
"--batch-all-objects");
+ else if (batch.nul_terminated)
+ usage_msg_optf(_("'%s' requires a batch mode"), usage, options,
+ "-z");
/* Batch defaults */
if (batch.buffer_output < 0)
diff --git a/t/t1006-cat-file.sh b/t/t1006-cat-file.sh
index 01c0535765..23b8942edb 100755
--- a/t/t1006-cat-file.sh
+++ b/t/t1006-cat-file.sh
@@ -88,7 +88,8 @@ done
for opt in --buffer \
--follow-symlinks \
- --batch-all-objects
+ --batch-all-objects \
+ -z
do
test_expect_success "usage: bad option combination: $opt without batch mode" '
test_incompatible_usage git cat-file $opt &&
@@ -100,6 +101,10 @@ echo_without_newline () {
printf '%s' "$*"
}
+echo_without_newline_nul () {
+ echo_without_newline "$@" | tr '\n' '\0'
+}
+
strlen () {
echo_without_newline "$1" | wc -c | sed -e 's/^ *//'
}
@@ -398,6 +403,12 @@ test_expect_success '--batch with multiple sha1s gives correct format' '
test "$(maybe_remove_timestamp "$batch_output" 1)" = "$(maybe_remove_timestamp "$(echo_without_newline "$batch_input" | git cat-file --batch)" 1)"
'
+test_expect_success '--batch, -z with multiple sha1s gives correct format' '
+ echo_without_newline_nul "$batch_input" >in &&
+ test "$(maybe_remove_timestamp "$batch_output" 1)" = \
+ "$(maybe_remove_timestamp "$(git cat-file --batch -z <in)" 1)"
+'
+
batch_check_input="$hello_sha1
$tree_sha1
$commit_sha1
@@ -418,6 +429,24 @@ test_expect_success "--batch-check with multiple sha1s gives correct format" '
"$(echo_without_newline "$batch_check_input" | git cat-file --batch-check)"
'
+test_expect_success "--batch-check, -z with multiple sha1s gives correct format" '
+ echo_without_newline_nul "$batch_check_input" >in &&
+ test "$batch_check_output" = "$(git cat-file --batch-check -z <in)"
+'
+
+test_expect_success FUNNYNAMES '--batch-check, -z with newline in input' '
+ touch -- "newline${LF}embedded" &&
+ git add -- "newline${LF}embedded" &&
+ git commit -m "file with newline embedded" &&
+ test_tick &&
+
+ printf "HEAD:newline${LF}embedded" >in &&
+ git cat-file --batch-check -z <in >actual &&
+
+ echo "$(git rev-parse "HEAD:newline${LF}embedded") blob 0" >expect &&
+ test_cmp expect actual
+'
+
batch_command_multiple_info="info $hello_sha1
info $tree_sha1
info $commit_sha1
@@ -436,6 +465,11 @@ test_expect_success '--batch-command with multiple info calls gives correct form
echo "$batch_command_multiple_info" >in &&
git cat-file --batch-command --buffer <in >actual &&
+ test_cmp expect actual &&
+
+ echo "$batch_command_multiple_info" | tr "\n" "\0" >in &&
+ git cat-file --batch-command --buffer -z <in >actual &&
+
test_cmp expect actual
'
@@ -459,6 +493,12 @@ test_expect_success '--batch-command with multiple command calls gives correct f
echo "$batch_command_multiple_contents" >in &&
git cat-file --batch-command --buffer <in >actual_raw &&
+ remove_timestamp <actual_raw >actual &&
+ test_cmp expect actual &&
+
+ echo "$batch_command_multiple_contents" | tr "\n" "\0" >in &&
+ git cat-file --batch-command --buffer -z <in >actual_raw &&
+
remove_timestamp <actual_raw >actual &&
test_cmp expect actual
'
--
2.37.0.1.g1379af2e9d
