find_reference_location(): make function safe for empty snapshots
This function had two problems if called for an empty snapshot (i.e., `snapshot->start == snapshot->eof == NULL`): * It checked `NULL < NULL`, which is undefined by C (albeit highly unlikely to fail in the real world). * (Assuming the above comparison behaved as expected), it returned NULL when `mustexist` was false, contrary to its docstring. Change the check and fix the docstring. Signed-off-by: Michael Haggerty <mhagger@alum.mit.edu> Signed-off-by: Junio C Hamano <gitster@pobox.com>
Michael Haggerty committed
Jan 24, 2018 at 12:14 UTC
4a14f8d093138a313070fd6a50204eda66c1f9eb
1 file changed
+6
-4
refs/packed-backend.c
+6
-4
@@ -519,9 +519,11 @@ static int load_contents(struct snapshot *snapshot)
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* `refname` starts. If `mustexist` is true and the reference doesn't
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* exist, then return NULL. If `mustexist` is false and the reference
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* doesn't exist, then return the point where that reference would be
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- * inserted. In the latter mode, `refname` doesn't have to be a proper
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- * reference name; for example, one could search for "refs/replace/"
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- * to find the start of any replace references.
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+ * inserted, or `snapshot->eof` (which might be NULL) if it would be
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+ * inserted at the end of the file. In the latter mode, `refname`
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+ * doesn't have to be a proper reference name; for example, one could
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+ * search for "refs/replace/" to find the start of any replace
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+ * references.
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*
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* The record is sought using a binary search, so `snapshot->buf` must
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* be sorted.
@@ -551,7 +553,7 @@ static const char *find_reference_location(struct snapshot *snapshot,
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*/
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const char *hi = snapshot->eof;
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- while (lo < hi) {
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+ while (lo != hi) {
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const char *mid, *rec;
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int cmp;
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