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Revision e88aab917e0dc3e99af8fb0f3ecbef66ac3e49b6 authored by Derrick Stolee on 24 October 2019, 13:40:41 UTC, committed by Junio C Hamano on 25 October 2019, 02:19:14 UTC 
t5510-fetch.sh: demonstrate fetch.writeCommitGraph bug
 
While dogfooding, Johannes found a bug in the fetch.writeCommitGraph
config behavior. His example initially happened during a clone with
--recurse-submodules, we found that this happens with the first fetch
after cloning a repository that contains a submodule:

	$ git clone <url> test
	$ cd test
	$ git -c fetch.writeCommitGraph=true fetch origin
	Computing commit graph generation numbers: 100% (12/12), done.
	BUG: commit-graph.c:886: missing parent <hash1> for commit <hash2>
	Aborted (core dumped)

In the repo I had cloned, there were really 60 commits to scan, but
only 12 were in the list to write when calling
compute_generation_numbers(). A commit in the list expects to see a
parent, but that parent is not in the list.

A follow-up will fix the bug, but first we create a test that
demonstrates the problem. This test must be careful about an existing
commit-graph file, since GIT_TEST_COMMIT_GRAPH=1 will cause the repo we
are cloning to already have one. This then prevents the incremtnal
commit-graph write during the first 'git fetch'.

Helped-by: Jeff King <peff@peff.net>
Helped-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Helped-by: Szeder Gábor <szeder.dev@gmail.com>
Signed-off-by: Derrick Stolee <dstolee@microsoft.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
1 parent 50f26bd
Raw File
hex.c 
#include "cache.h"

const signed char hexval_table[256] = {
	 -1, -1, -1, -1, -1, -1, -1, -1,		/* 00-07 */
	 -1, -1, -1, -1, -1, -1, -1, -1,		/* 08-0f */
	 -1, -1, -1, -1, -1, -1, -1, -1,		/* 10-17 */
	 -1, -1, -1, -1, -1, -1, -1, -1,		/* 18-1f */
	 -1, -1, -1, -1, -1, -1, -1, -1,		/* 20-27 */
	 -1, -1, -1, -1, -1, -1, -1, -1,		/* 28-2f */
	  0,  1,  2,  3,  4,  5,  6,  7,		/* 30-37 */
	  8,  9, -1, -1, -1, -1, -1, -1,		/* 38-3f */
	 -1, 10, 11, 12, 13, 14, 15, -1,		/* 40-47 */
	 -1, -1, -1, -1, -1, -1, -1, -1,		/* 48-4f */
	 -1, -1, -1, -1, -1, -1, -1, -1,		/* 50-57 */
	 -1, -1, -1, -1, -1, -1, -1, -1,		/* 58-5f */
	 -1, 10, 11, 12, 13, 14, 15, -1,		/* 60-67 */
	 -1, -1, -1, -1, -1, -1, -1, -1,		/* 68-67 */
	 -1, -1, -1, -1, -1, -1, -1, -1,		/* 70-77 */
	 -1, -1, -1, -1, -1, -1, -1, -1,		/* 78-7f */
	 -1, -1, -1, -1, -1, -1, -1, -1,		/* 80-87 */
	 -1, -1, -1, -1, -1, -1, -1, -1,		/* 88-8f */
	 -1, -1, -1, -1, -1, -1, -1, -1,		/* 90-97 */
	 -1, -1, -1, -1, -1, -1, -1, -1,		/* 98-9f */
	 -1, -1, -1, -1, -1, -1, -1, -1,		/* a0-a7 */
	 -1, -1, -1, -1, -1, -1, -1, -1,		/* a8-af */
	 -1, -1, -1, -1, -1, -1, -1, -1,		/* b0-b7 */
	 -1, -1, -1, -1, -1, -1, -1, -1,		/* b8-bf */
	 -1, -1, -1, -1, -1, -1, -1, -1,		/* c0-c7 */
	 -1, -1, -1, -1, -1, -1, -1, -1,		/* c8-cf */
	 -1, -1, -1, -1, -1, -1, -1, -1,		/* d0-d7 */
	 -1, -1, -1, -1, -1, -1, -1, -1,		/* d8-df */
	 -1, -1, -1, -1, -1, -1, -1, -1,		/* e0-e7 */
	 -1, -1, -1, -1, -1, -1, -1, -1,		/* e8-ef */
	 -1, -1, -1, -1, -1, -1, -1, -1,		/* f0-f7 */
	 -1, -1, -1, -1, -1, -1, -1, -1,		/* f8-ff */
};

int hex_to_bytes(unsigned char *binary, const char *hex, size_t len)
{
	for (; len; len--, hex += 2) {
		unsigned int val = (hexval(hex[0]) << 4) | hexval(hex[1]);

		if (val & ~0xff)
			return -1;
		*binary++ = val;
	}
	return 0;
}

int get_sha1_hex(const char *hex, unsigned char *sha1)
{
	int i;
	for (i = 0; i < the_hash_algo->rawsz; i++) {
		int val = hex2chr(hex);
		if (val < 0)
			return -1;
		*sha1++ = val;
		hex += 2;
	}
	return 0;
}

int get_oid_hex(const char *hex, struct object_id *oid)
{
	return get_sha1_hex(hex, oid->hash);
}

int parse_oid_hex(const char *hex, struct object_id *oid, const char **end)
{
	int ret = get_oid_hex(hex, oid);
	if (!ret)
		*end = hex + the_hash_algo->hexsz;
	return ret;
}

char *hash_to_hex_algop_r(char *buffer, const unsigned char *hash,
			  const struct git_hash_algo *algop)
{
	static const char hex[] = "0123456789abcdef";
	char *buf = buffer;
	int i;

	for (i = 0; i < algop->rawsz; i++) {
		unsigned int val = *hash++;
		*buf++ = hex[val >> 4];
		*buf++ = hex[val & 0xf];
	}
	*buf = '\0';

	return buffer;
}

char *sha1_to_hex_r(char *buffer, const unsigned char *sha1)
{
	return hash_to_hex_algop_r(buffer, sha1, &hash_algos[GIT_HASH_SHA1]);
}

char *oid_to_hex_r(char *buffer, const struct object_id *oid)
{
	return hash_to_hex_algop_r(buffer, oid->hash, the_hash_algo);
}

char *hash_to_hex_algop(const unsigned char *hash, const struct git_hash_algo *algop)
{
	static int bufno;
	static char hexbuffer[4][GIT_MAX_HEXSZ + 1];
	bufno = (bufno + 1) % ARRAY_SIZE(hexbuffer);
	return hash_to_hex_algop_r(hexbuffer[bufno], hash, algop);
}

char *sha1_to_hex(const unsigned char *sha1)
{
	return hash_to_hex_algop(sha1, &hash_algos[GIT_HASH_SHA1]);
}

char *hash_to_hex(const unsigned char *hash)
{
	return hash_to_hex_algop(hash, the_hash_algo);
}

char *oid_to_hex(const struct object_id *oid)
{
	return hash_to_hex_algop(oid->hash, the_hash_algo);
}
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