diff options
| -rw-r--r-- | Documentation/git-push.txt | 77 | ||||
| -rw-r--r-- | builtin/push.c | 6 | ||||
| -rw-r--r-- | builtin/send-pack.c | 17 | ||||
| -rw-r--r-- | remote.c | 57 | ||||
| -rw-r--r-- | remote.h | 22 |
5 files changed, 168 insertions, 11 deletions
diff --git a/Documentation/git-push.txt b/Documentation/git-push.txt index f7dfe48d2..e2992f17a 100644 --- a/Documentation/git-push.txt +++ b/Documentation/git-push.txt @@ -11,6 +11,7 @@ SYNOPSIS [verse] 'git push' [--all | --mirror | --tags] [--follow-tags] [-n | --dry-run] [--receive-pack=<git-receive-pack>] [--repo=<repository>] [-f | --force] [--prune] [-v | --verbose] [-u | --set-upstream] + [--force-with-lease[=<refname>[:<expect>]]] [--no-verify] [<repository> [<refspec>...]] DESCRIPTION @@ -130,21 +131,75 @@ already exists on the remote side. repository over ssh, and you do not have the program in a directory on the default $PATH. +--[no-]force-with-lease:: +--force-with-lease=<refname>:: +--force-with-lease=<refname>:<expect>:: + Usually, "git push" refuses to update a remote ref that is + not an ancestor of the local ref used to overwrite it. ++ +This option bypasses the check, but instead requires that the +current value of the ref to be the expected value. "git push" +fails otherwise. ++ +Imagine that you have to rebase what you have already published. +You will have to bypass the "must fast-forward" rule in order to +replace the history you originally published with the rebased history. +If somebody else built on top of your original history while you are +rebasing, the tip of the branch at the remote may advance with her +commit, and blindly pushing with `--force` will lose her work. ++ +This option allows you to say that you expect the history you are +updating is what you rebased and want to replace. If the remote ref +still points at the commit you specified, you can be sure that no +other people did anything to the ref (it is like taking a "lease" on +the ref without explicitly locking it, and you update the ref while +making sure that your earlier "lease" is still valid). ++ +`--force-with-lease` alone, without specifying the details, will protect +all remote refs that are going to be updated by requiring their +current value to be the same as the remote-tracking branch we have +for them, unless specified with a `--force-with-lease=<refname>:<expect>` +option that explicitly states what the expected value is. ++ +`--force-with-lease=<refname>`, without specifying the expected value, will +protect the named ref (alone), if it is going to be updated, by +requiring its current value to be the same as the remote-tracking +branch we have for it. ++ +`--force-with-lease=<refname>:<expect>` will protect the named ref (alone), +if it is going to be updated, by requiring its current value to be +the same as the specified value <expect> (which is allowed to be +different from the remote-tracking branch we have for the refname, +or we do not even have to have such a remote-tracking branch when +this form is used). ++ +Note that all forms other than `--force-with-lease=<refname>:<expect>` +that specifies the expected current value of the ref explicitly are +still experimental and their semantics may change as we gain experience +with this feature. ++ +"--no-force-with-lease" will cancel all the previous --force-with-lease on the +command line. + -f:: --force:: Usually, the command refuses to update a remote ref that is not an ancestor of the local ref used to overwrite it. - This flag disables the check. This can cause the - remote repository to lose commits; use it with care. - Note that `--force` applies to all the refs that are pushed, - hence using it with `push.default` set to `matching` or with - multiple push destinations configured with `remote.*.push` - may overwrite refs other than the current branch (including - local refs that are strictly behind their remote counterpart). - To force a push to only one branch, use a `+` in front of the - refspec to push (e.g `git push origin +master` to force a push - to the `master` branch). See the `<refspec>...` section above - for details. + Also, when `--force-with-lease` option is used, the command refuses + to update a remote ref whose current value does not match + what is expected. ++ +This flag disables these checks, and can cause the remote repository +to lose commits; use it with care. ++ +Note that `--force` applies to all the refs that are pushed, hence +using it with `push.default` set to `matching` or with multiple push +destinations configured with `remote.*.push` may overwrite refs +other than the current branch (including local refs that are +strictly behind their remote counterpart). To force a push to only +one branch, use a `+` in front of the refspec to push (e.g `git push +origin +master` to force a push to the `master` branch). See the +`<refspec>...` section above for details. --repo=<repository>:: This option is only relevant if no <repository> argument is diff --git a/builtin/push.c b/builtin/push.c index 342d792f9..31a5ba085 100644 --- a/builtin/push.c +++ b/builtin/push.c @@ -21,6 +21,8 @@ static const char *receivepack; static int verbosity; static int progress = -1; +static struct push_cas_option cas; + static const char **refspec; static int refspec_nr; static int refspec_alloc; @@ -432,6 +434,10 @@ int cmd_push(int argc, const char **argv, const char *prefix) OPT_BIT('n' , "dry-run", &flags, N_("dry run"), TRANSPORT_PUSH_DRY_RUN), OPT_BIT( 0, "porcelain", &flags, N_("machine-readable output"), TRANSPORT_PUSH_PORCELAIN), OPT_BIT('f', "force", &flags, N_("force updates"), TRANSPORT_PUSH_FORCE), + { OPTION_CALLBACK, + 0, CAS_OPT_NAME, &cas, N_("refname>:<expect"), + N_("require old value of ref to be at this value"), + PARSE_OPT_OPTARG, parseopt_push_cas_option }, { OPTION_CALLBACK, 0, "recurse-submodules", &flags, N_("check"), N_("control recursive pushing of submodules"), PARSE_OPT_OPTARG, option_parse_recurse_submodules }, diff --git a/builtin/send-pack.c b/builtin/send-pack.c index e86d3b5d6..a23b26db1 100644 --- a/builtin/send-pack.c +++ b/builtin/send-pack.c @@ -103,6 +103,7 @@ int cmd_send_pack(int argc, const char **argv, const char *prefix) int flags; unsigned int reject_reasons; int progress = -1; + struct push_cas_option cas = {0}; argv++; for (i = 1; i < argc; i++, argv++) { @@ -165,6 +166,22 @@ int cmd_send_pack(int argc, const char **argv, const char *prefix) helper_status = 1; continue; } + if (!strcmp(arg, "--" CAS_OPT_NAME)) { + if (parse_push_cas_option(&cas, NULL, 0) < 0) + exit(1); + continue; + } + if (!strcmp(arg, "--no-" CAS_OPT_NAME)) { + if (parse_push_cas_option(&cas, NULL, 1) < 0) + exit(1); + continue; + } + if (!prefixcmp(arg, "--" CAS_OPT_NAME "=")) { + if (parse_push_cas_option(&cas, + strchr(arg, '=') + 1, 1) < 0) + exit(1); + continue; + } usage(send_pack_usage); } if (!dest) { @@ -1921,3 +1921,60 @@ struct ref *get_stale_heads(struct refspec *refs, int ref_count, struct ref *fet string_list_clear(&ref_names, 0); return stale_refs; } + +/* + * Compare-and-swap + */ +void clear_cas_option(struct push_cas_option *cas) +{ + int i; + + for (i = 0; i < cas->nr; i++) + free(cas->entry[i].refname); + free(cas->entry); + memset(cas, 0, sizeof(*cas)); +} + +static struct push_cas *add_cas_entry(struct push_cas_option *cas, + const char *refname, + size_t refnamelen) +{ + struct push_cas *entry; + ALLOC_GROW(cas->entry, cas->nr + 1, cas->alloc); + entry = &cas->entry[cas->nr++]; + memset(entry, 0, sizeof(*entry)); + entry->refname = xmemdupz(refname, refnamelen); + return entry; +} + +int parse_push_cas_option(struct push_cas_option *cas, const char *arg, int unset) +{ + const char *colon; + struct push_cas *entry; + + if (unset) { + /* "--no-<option>" */ + clear_cas_option(cas); + return 0; + } + + if (!arg) { + /* just "--<option>" */ + cas->use_tracking_for_rest = 1; + return 0; + } + + /* "--<option>=refname" or "--<option>=refname:value" */ + colon = strchrnul(arg, ':'); + entry = add_cas_entry(cas, arg, colon - arg); + if (!*colon) + entry->use_tracking = 1; + else if (get_sha1(colon + 1, entry->expect)) + return error("cannot parse expected object name '%s'", colon + 1); + return 0; +} + +int parseopt_push_cas_option(const struct option *opt, const char *arg, int unset) +{ + return parse_push_cas_option(opt->value, arg, unset); +} @@ -1,6 +1,8 @@ #ifndef REMOTE_H #define REMOTE_H +#include "parse-options.h" + enum { REMOTE_CONFIG, REMOTE_REMOTES, @@ -226,4 +228,24 @@ struct ref *guess_remote_head(const struct ref *head, /* Return refs which no longer exist on remote */ struct ref *get_stale_heads(struct refspec *refs, int ref_count, struct ref *fetch_map); +/* + * Compare-and-swap + */ +#define CAS_OPT_NAME "force-with-lease" + +struct push_cas_option { + unsigned use_tracking_for_rest:1; + struct push_cas { + unsigned char expect[20]; + unsigned use_tracking:1; + char *refname; + } *entry; + int nr; + int alloc; +}; + +extern int parseopt_push_cas_option(const struct option *, const char *arg, int unset); +extern int parse_push_cas_option(struct push_cas_option *, const char *arg, int unset); +extern void clear_cas_option(struct push_cas_option *); + #endif |