Staging
v0.7.0
v0.7.0
Revision cb99a34e23e32ca8e94bafaa9699cfd133a17fd3 authored by Derrick Stolee on 24 October 2019, 13:40:42 UTC, committed by Junio C Hamano on 25 October 2019, 02:19:16 UTC
The previous commit includes a failing test for an issue around fetch.writeCommitGraph and fetching in a repo with a submodule. Here, we fix that bug and set the test to "test_expect_success". The problem arises with this set of commands when the remote repo at <url> has a submodule. Note that --recurse-submodules is not needed to demonstrate the bug. $ 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) As an initial fix, I converted the code in builtin/fetch.c that calls write_commit_graph_reachable() to instead launch a "git commit-graph write --reachable --split" process. That code worked, but is not how we want the feature to work long-term. That test did demonstrate that the issue must be something to do with internal state of the 'git fetch' process. The write_commit_graph() method in commit-graph.c ensures the commits we plan to write are "closed under reachability" using close_reachable(). This method walks from the input commits, and uses the UNINTERESTING flag to mark which commits have already been visited. This allows the walk to take O(N) time, where N is the number of commits, instead of O(P) time, where P is the number of paths. (The number of paths can be exponential in the number of commits.) However, the UNINTERESTING flag is used in lots of places in the codebase. This flag usually means some barrier to stop a commit walk, such as in revision-walking to compare histories. It is not often cleared after the walk completes because the starting points of those walks do not have the UNINTERESTING flag, and clear_commit_marks() would stop immediately. This is happening during a 'git fetch' call with a remote. The fetch negotiation is comparing the remote refs with the local refs and marking some commits as UNINTERESTING. I tested running clear_commit_marks_many() to clear the UNINTERESTING flag inside close_reachable(), but the tips did not have the flag, so that did nothing. It turns out that the calculate_changed_submodule_paths() method is at fault. Thanks, Peff, for pointing out this detail! More specifically, for each submodule, the collect_changed_submodules() runs a revision walk to essentially do file-history on the list of submodules. That revision walk marks commits UNININTERESTING if they are simplified away by not changing the submodule. Instead, I finally arrived on the conclusion that I should use a flag that is not used in any other part of the code. In commit-reach.c, a number of flags were defined for commit walk algorithms. The REACHABLE flag seemed like it made the most sense, and it seems it was not actually used in the file. The REACHABLE flag was used in early versions of commit-reach.c, but was removed by 4fbcca4 (commit-reach: make can_all_from_reach... linear, 2018-07-20). Add the REACHABLE flag to commit-graph.c and use it instead of UNINTERESTING in close_reachable(). This fixes the bug in manual testing. Reported-by: Johannes Schindelin <johannes.schindelin@gmx.de> Helped-by: Jeff King <peff@peff.net> 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>
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urlmatch.h
#ifndef URL_MATCH_H
#define URL_MATCH_H
#include "string-list.h"
struct url_info {
/* normalized url on success, must be freed, otherwise NULL */
char *url;
/* if !url, a brief reason for the failure, otherwise NULL */
const char *err;
/* the rest of the fields are only set if url != NULL */
size_t url_len; /* total length of url (which is now normalized) */
size_t scheme_len; /* length of scheme name (excluding final :) */
size_t user_off; /* offset into url to start of user name (0 => none) */
size_t user_len; /* length of user name; if user_off != 0 but
user_len == 0, an empty user name was given */
size_t passwd_off; /* offset into url to start of passwd (0 => none) */
size_t passwd_len; /* length of passwd; if passwd_off != 0 but
passwd_len == 0, an empty passwd was given */
size_t host_off; /* offset into url to start of host name (0 => none) */
size_t host_len; /* length of host name;
* file urls may have host_len == 0 */
size_t port_off; /* offset into url to start of port number (0 => none) */
size_t port_len; /* if a portnum is present (port_off != 0), it has
* this length (excluding the leading ':') starting
* from port_off (always 0 for file urls) */
size_t path_off; /* offset into url to the start of the url path;
* this will always point to a '/' character
* after the url has been normalized */
size_t path_len; /* length of path portion excluding any trailing
* '?...' and '#...' portion; will always be >= 1 */
};
char *url_normalize(const char *, struct url_info *);
struct urlmatch_item {
size_t hostmatch_len;
size_t pathmatch_len;
char user_matched;
};
struct urlmatch_config {
struct string_list vars;
struct url_info url;
const char *section;
const char *key;
void *cb;
int (*collect_fn)(const char *var, const char *value, void *cb);
int (*cascade_fn)(const char *var, const char *value, void *cb);
};
int urlmatch_config_entry(const char *var, const char *value, void *cb);
#endif /* URL_MATCH_H */
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