[PATCH 1/6] log_tree_diff: die when we fail to parse a commit
We currently call parse_commit and then assume we can dereference the resulting "tree" struct field. If parsing failed, however, that field is NULL and we end up segfaulting.
Instead of a segfault, let's print an error message and die a little more gracefully.
Note that this should never happen in practice, but may happen in a corrupt repository.
Signed-off-by: Jeff King <peff@peff.net>
---
commit.c | 7 +++++++
commit.h | 1 +
log-tree.c | 6 +++---
3 files changed, 11 insertions(+), 3 deletions(-)
Show changes to 3 files +11 −3
commit.c, commit.h, log-tree.c
diff --git a/commit.c b/commit.c
index de16a3c..51a9bbc 100644
--- a/commit.c
+++ b/commit.c
@@ -341,6 +341,13 @@ int parse_commit(struct commit *item)
return ret;
}
+void parse_commit_or_die(struct commit *item)
+{
+ if (parse_commit(item))
+ die("unable to parse commit %s",
+ item ? sha1_to_hex(item->object.sha1) : "(null)");
+}
+
int find_commit_subject(const char *commit_buffer, const char **subject)
{
const char *eol;
diff --git a/commit.h b/commit.h
index bd841f4..934af88 100644
--- a/commit.h
+++ b/commit.h
@@ -49,6 +49,7 @@ struct commit *lookup_commit_or_die(const unsigned char *sha1, const char *ref_n
int parse_commit_buffer(struct commit *item, const void *buffer, unsigned long size);
int parse_commit(struct commit *item);
+void parse_commit_or_die(struct commit *item);
/* Find beginning and length of commit subject. */
int find_commit_subject(const char *commit_buffer, const char **subject);
diff --git a/log-tree.c b/log-tree.c
index 8534d91..e958d07 100644
--- a/log-tree.c
+++ b/log-tree.c
@@ -734,7 +734,7 @@ static int log_tree_diff(struct rev_info *opt, struct commit *commit, struct log
if (!opt->diff && !DIFF_OPT_TST(&opt->diffopt, EXIT_WITH_STATUS))
return 0;
- parse_commit(commit);
+ parse_commit_or_die(commit);
sha1 = commit->tree->object.sha1;
/* Root commit? */
@@ -759,7 +759,7 @@ static int log_tree_diff(struct rev_info *opt, struct commit *commit, struct log
* parent, showing summary diff of the others
* we merged _in_.
*/
- parse_commit(parents->item);
+ parse_commit_or_die(parents->item);
diff_tree_sha1(parents->item->tree->object.sha1,
sha1, "", &opt->diffopt);
log_tree_diff_flush(opt);
@@ -774,7 +774,7 @@ static int log_tree_diff(struct rev_info *opt, struct commit *commit, struct log
for (;;) {
struct commit *parent = parents->item;
- parse_commit(parent);
+ parse_commit_or_die(parent);
diff_tree_sha1(parent->tree->object.sha1,
sha1, "", &opt->diffopt);
log_tree_diff_flush(opt);
--
1.8.4.1.898.g8bf8a41.dirty
Jeff King