get_sha1: detect buggy calls with multiple disambiguators
The get_sha1() family of functions takes a flags field, but some of the flags are mutually exclusive. In particular, we can only handle one disambiguating function, and the flags quietly override each other. Let's instead detect these as programming bugs. Technically some of the flags are supersets of the others, so treating COMMITTISH|TREEISH as just COMMITTISH is not wrong, but it's a good sign the caller is confused. And certainly asking for BLOB|TREE does not work. We can do the check easily with some bit-twiddling, and as a bonus, the bit-mask of disambiguators will come in handy in a future patch. Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
Jeff King committed
Sep 26, 2016 at 07:59 UTC
259942f549eb235e9d7d095c2db8f3dc279f3958
2 files changed
+9
cache.h
+5
@@ -1203,6 +1203,11 @@ struct object_context {
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#define GET_SHA1_FOLLOW_SYMLINKS 0100
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#define GET_SHA1_ONLY_TO_DIE 04000
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+#define GET_SHA1_DISAMBIGUATORS \
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+ (GET_SHA1_COMMIT | GET_SHA1_COMMITTISH | \
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+ GET_SHA1_TREE | GET_SHA1_TREEISH | \
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+ GET_SHA1_BLOB)
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+
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extern int get_sha1(const char *str, unsigned char *sha1);
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extern int get_sha1_commit(const char *str, unsigned char *sha1);
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extern int get_sha1_committish(const char *str, unsigned char *sha1);
sha1_name.c
+4
@@ -327,6 +327,10 @@ static int get_short_sha1(const char *name, int len, unsigned char *sha1,
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prepare_alt_odb();
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memset(&ds, 0, sizeof(ds));
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+
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+ if (HAS_MULTI_BITS(flags & GET_SHA1_DISAMBIGUATORS))
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+ die("BUG: multiple get_short_sha1 disambiguator flags");
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+
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if (flags & GET_SHA1_COMMIT)
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ds.fn = disambiguate_commit_only;
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else if (flags & GET_SHA1_COMMITTISH)