fast-export: fix anonymized tag using original length

From: Tal Kelrich <[email protected]>

Commit 7f4075949686 (fast-export: tighten anonymize_mem() interface to handle only strings, 2020-06-23) changed the interface used in anonymizing strings, but failed to update the size of annotated tag messages to match the new anonymized string.

As a result, exporting tags having messages longer than 13 characters would create output that couldn't be parsed by fast-import, as the data length indicated was larger than the data output.

Reset the message size when anonymizing, and add a tag with a "long" message to the test.

---
fast-export: fix anonymized tag using original length

Fixes an issue with fast-export anonymization, where any original annotated tag message longer than 13 characters would make the output unimportable by fast-import (as the data length indicated the original length).

This also resolves a more minor issue, where if the original message was short, the anonymized tag message would be truncated.

Published-As: https://github.com/gitgitgadget/git/releases/tag/pr-1030%2Fhasturkun%2Ffast-export-tag-length-v1
Fetch-It-Via: git fetch https://github.com/gitgitgadget/git pr-1030/hasturkun/fast-export-tag-length-v1
Pull-Request: https://github.com/gitgitgadget/git/pull/1030

 builtin/fast-export.c            |  1 +
 t/t9351-fast-export-anonymize.sh | 10 ++++++----
 2 files changed, 7 insertions(+), 4 deletions(-)

index 3c20f164f0f..95e8e89e81f 100644
@@ -821,6 +821,7 @@ static void handle_tag(const char *name, struct tag *tag)
 			static struct hashmap tags;
 			message = anonymize_str(&tags, anonymize_tag,
 						message, message_size, NULL);
+			message_size = strlen(message);
 		}
 	}
 

index 1c6e6fcdaf3..77047e250dc 100755
@@ -18,7 +18,8 @@ test_expect_success 'setup simple repo' '
 	git update-index --add --cacheinfo 160000,$fake_commit,link1 &&
 	git update-index --add --cacheinfo 160000,$fake_commit,link2 &&
 	git commit -m "add gitlink" &&
-	git tag -m "annotated tag" mytag
+	git tag -m "annotated tag" mytag &&
+	git tag -m "annotated tag with long message" longtag
 '
 
 test_expect_success 'export anonymized stream' '

@@ -55,7 +56,8 @@ test_expect_success 'stream retains other as refname' '
 
 test_expect_success 'stream omits other refnames' '
 	! grep main stream &&
-	! grep mytag stream
+	! grep mytag stream &&
+	! grep longtag stream
 '
 
 test_expect_success 'stream omits identities' '

@@ -118,9 +120,9 @@ test_expect_success 'identical gitlinks got identical oid' '
 	test_line_count = 1 commits
 '
 
-test_expect_success 'tag points to branch tip' '
+test_expect_success 'all tags point to branch tip' '
 	git rev-parse $other_branch >expect &&
-	git for-each-ref --format="%(*objectname)" | grep . >actual &&
+	git for-each-ref --format="%(*objectname)" | grep . | uniq >actual &&
 	test_cmp expect actual
 '
 

base-commit: 6c40894d2466d4e7fddc047a05116aa9d14712ee

gitgitgadget

Thanks. I've looked at all places where anonymize_str() is used and found that this is the only problematic caller.

Will queue.

Thanks, good catch and nicely explained. I wondered where the "13" came from, and it is "tag message %d" (so really, it depends how many tags you have :) ).