[PATCH v2 04/15] bundle-uri: handle NULL value for fetch.bundleCreationToken

["Thomas Bachem via GitGitGadget" <gitgitgadget@gmail.com>]

From: Thomas Bachem <mail@thomasbachem.com>

A fetch.bundleCreationToken without a value makes "git fetch" and
"git clone --bundle-uri" segfault when the bundle list uses the
creationToken heuristic: fetch_bundles_by_token() passes the NULL
value to sscanf().

The function already treats a token that does not parse as 0, as if
no bundles had been fetched before, so it downloads them and then
stores the new token. Treat a missing value the same way.

Assisted-by: Claude Fable 5.1
Signed-off-by: Thomas Bachem <mail@thomasbachem.com>
---
 bundle-uri.c                |  3 ++-
 t/t5558-clone-bundle-uri.sh | 20 ++++++++++++++++++++
 2 files changed, 22 insertions(+), 1 deletion(-)

diff --git a/bundle-uri.c b/bundle-uri.c
index 9797eaed9a..67a717e857 100644
--- a/bundle-uri.c
+++ b/bundle-uri.c
@@ -572,7 +572,8 @@ static int fetch_bundles_by_token(struct repository *r,
 	if (!repo_config_get_value(r,
 				   "fetch.bundlecreationtoken",
 				   &creationTokenStr)) {
-		if (sscanf(creationTokenStr, "%"PRIu64, &maxCreationToken) != 1)
+		if (!creationTokenStr ||
+		    sscanf(creationTokenStr, "%"PRIu64, &maxCreationToken) != 1)
 			maxCreationToken = 0;
 		if (bundles.items[0]->creationToken <= maxCreationToken) {
 			free(bundles.items);
diff --git a/t/t5558-clone-bundle-uri.sh b/t/t5558-clone-bundle-uri.sh
index f81f1f8db7..e86ed7d30c 100755
--- a/t/t5558-clone-bundle-uri.sh
+++ b/t/t5558-clone-bundle-uri.sh
@@ -346,6 +346,26 @@ test_expect_success 'clone bundle list (file, any mode, all failures)' '
 	test_grep ! "refs/bundles/heads/" refs
 '
 
+test_expect_success 'fetch treats fetch.bundleCreationToken without a value as 0' '
+	test_when_finished "rm -rf token-without-value" &&
+	cat >bundle-list <<-EOF &&
+	[bundle]
+		version = 1
+		mode = all
+		heuristic = creationToken
+
+	[bundle "bundle-1"]
+		uri = file://$(pwd)/clone-from/bundle-1.bundle
+		creationToken = 1
+	EOF
+
+	git clone --no-local clone-from token-without-value &&
+	git -C token-without-value \
+		-c fetch.bundleURI="file://$(pwd)/bundle-list" \
+		-c fetch.bundleCreationToken fetch origin &&
+	test_cmp_config -C token-without-value 1 fetch.bundlecreationtoken
+'
+
 test_expect_success 'negotiation: bundle with part of wanted commits' '
 	test_when_finished "rm -f trace*.txt" &&
 	GIT_TRACE_PACKET="$(pwd)/trace-packet.txt" \
-- 
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