get_commit_tree(): return NULL for broken tree
Return NULL from 'get_commit_tree()' when a commit's root tree is corrupt, doesn't exist, or points to an object which is not a tree. In [1], this situation became a BUG(), but it can certainly occur in cases which are not a bug in Git, for e.g., if a caller manually crafts a commit whose tree is corrupt in any of the above ways. Note that the expect_failure test in t6102 triggers this BUG(), but we can't flip it to expect_success yet. Solving this problem actually reveals a second bug. [1]: 7b8a21dba1 (commit-graph: lazy-load trees for commits, 2018-04-06) Co-authored-by: Taylor Blau <me@ttaylorr.com> Signed-off-by: Taylor Blau <me@ttaylorr.com> Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
Jeff King committed
Apr 9, 2019 at 19:13 UTC
834876630b21f832f648bc46a753291e4512ca8f
1 file changed
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commit.c
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-3
@@ -345,10 +345,10 @@ struct tree *get_commit_tree(const struct commit *commit)
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if (commit->maybe_tree || !commit->object.parsed)
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return commit->maybe_tree;
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- if (commit->graph_pos == COMMIT_NOT_FROM_GRAPH)
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- BUG("commit has NULL tree, but was not loaded from commit-graph");
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+ if (commit->graph_pos != COMMIT_NOT_FROM_GRAPH)
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+ return get_commit_tree_in_graph(the_repository, commit);
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- return get_commit_tree_in_graph(the_repository, commit);
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+ return NULL;
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}
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struct object_id *get_commit_tree_oid(const struct commit *commit)