[PATCH v2 2/4] fast-export: anonymize "master" refname

From: Jeff King <peff@peff.net>
Date: Jun 22, 2020, 21:48 UTC
Message-ID: <20200622214802.GB3303964@coredump.intra.peff.net>
In-Reply-To: <20200622214745.GA3302779@coredump.intra.peff.net>

Running "fast-export --anonymize" will leave "refs/heads/master" untouched in the output, for two reasons:

  - it helped to have some known reference point between the original
    and anonymized repository

  - since it's historically the default branch name, it doesn't leak any
    information

Now that we can ask fast-export to dump the anonymized ref mapping, we have a much better tool for the first one (because it works for _any_ ref, not just master).

For the second, the notion of "default branch name" is likely to become configurable soon, at which point the name _does_ leak information. Let's drop this special case in preparation.

Note that we have to adjust the test a bit, since it relied on using the name "master" in the anonymized repos. But this gives us a good opportunity to further test the new dumping feature.

Signed-off-by: Jeff King <peff@peff.net>
---
 builtin/fast-export.c            |  7 -------
 t/t9351-fast-export-anonymize.sh | 15 +++++----------
 2 files changed, 5 insertions(+), 17 deletions(-)

diff --git a/builtin/fast-export.c b/builtin/fast-export.c
index 844726d45a..faaab6c7e9 100644
--- a/builtin/fast-export.c
+++ b/builtin/fast-export.c
@@ -538,13 +538,6 @@ static const char *anonymize_refname(const char *refname)
 	const char *full_refname = refname;
 	int i;
 
-	/*
-	 * We also leave "master" as a special case, since it does not reveal
-	 * anything interesting.
-	 */
-	if (!strcmp(refname, "refs/heads/master"))
-		return refname;
-
 	strbuf_reset(&anon);
 	for (i = 0; i < ARRAY_SIZE(prefixes); i++) {
 		if (skip_prefix(refname, prefixes[i], &refname)) {
diff --git a/t/t9351-fast-export-anonymize.sh b/t/t9351-fast-export-anonymize.sh
index 75cbc7b329..c726306c4d 100755
--- a/t/t9351-fast-export-anonymize.sh
+++ b/t/t9351-fast-export-anonymize.sh
@@ -26,11 +26,8 @@ test_expect_success 'stream omits path names' '
 	! grep xyzzy stream
 '
 
-test_expect_success 'stream allows master as refname' '
-	grep master stream
-'
-
-test_expect_success 'stream omits other refnames' '
+test_expect_success 'stream omits refnames' '
+	! grep master stream &&
 	! grep other stream &&
 	! grep mytag stream
 '
@@ -53,9 +50,6 @@ test_expect_success 'refname mapping can be dumped' '
 	# so just check that we have the right number and
 	# that a sample line looks sane.
 	expected_count=$(git for-each-ref | wc -l) &&
-	# Note that master is not anonymized, and so not included
-	# in the mapping.
-	expected_count=$((expected_count - 1)) &&
 	test_line_count = $expected_count refs.out &&
 	grep "^refs/heads/other refs/heads/" refs.out
 '
@@ -71,15 +65,16 @@ test_expect_success 'import stream to new repository' '
 test_expect_success 'result has two branches' '
 	git for-each-ref --format="%(refname)" refs/heads >branches &&
 	test_line_count = 2 branches &&
-	other_branch=$(grep -v refs/heads/master branches)
+	main_branch=$(sed -ne "s,refs/heads/master ,,p" ../refs.out) &&
+	other_branch=$(sed -ne "s,refs/heads/other ,,p" ../refs.out)
 '
 
 test_expect_success 'repo has original shape and timestamps' '
 	shape () {
 		git log --format="%m %ct" --left-right --boundary "$@"
 	} &&
 	(cd .. && shape master...other) >expect &&
-	shape master...$other_branch >actual &&
+	shape $main_branch...$other_branch >actual &&
 	test_cmp expect actual
 '

-- 
2.27.0.517.gbc32778fa3