diff options
Diffstat (limited to 'sha1_name.c')
| -rw-r--r-- | sha1_name.c | 127 |
1 files changed, 123 insertions, 4 deletions
diff --git a/sha1_name.c b/sha1_name.c index 722fc35a6d..5d0ac0263d 100644 --- a/sha1_name.c +++ b/sha1_name.c @@ -238,8 +238,28 @@ static int ambiguous_path(const char *path, int len) return slash; } +/* + * *string and *len will only be substituted, and *string returned (for + * later free()ing) if the string passed in is of the form @{-<n>}. + */ +static char *substitute_nth_last_branch(const char **string, int *len) +{ + struct strbuf buf = STRBUF_INIT; + int ret = interpret_nth_last_branch(*string, &buf); + + if (ret == *len) { + size_t size; + *string = strbuf_detach(&buf, &size); + *len = size; + return (char *)*string; + } + + return NULL; +} + int dwim_ref(const char *str, int len, unsigned char *sha1, char **ref) { + char *last_branch = substitute_nth_last_branch(&str, &len); const char **p, *r; int refs_found = 0; @@ -259,11 +279,13 @@ int dwim_ref(const char *str, int len, unsigned char *sha1, char **ref) break; } } + free(last_branch); return refs_found; } int dwim_log(const char *str, int len, unsigned char *sha1, char **log) { + char *last_branch = substitute_nth_last_branch(&str, &len); const char **p; int logs_found = 0; @@ -294,9 +316,12 @@ int dwim_log(const char *str, int len, unsigned char *sha1, char **log) if (!warn_ambiguous_refs) break; } + free(last_branch); return logs_found; } +static int get_sha1_1(const char *name, int len, unsigned char *sha1); + static int get_sha1_basic(const char *str, int len, unsigned char *sha1) { static const char *warning = "warning: refname '%.*s' is ambiguous.\n"; @@ -307,10 +332,10 @@ static int get_sha1_basic(const char *str, int len, unsigned char *sha1) if (len == 40 && !get_sha1_hex(str, sha1)) return 0; - /* basic@{time or number} format to query ref-log */ + /* basic@{time or number or -number} format to query ref-log */ reflog_len = at = 0; if (len && str[len-1] == '}') { - for (at = 0; at < len - 1; at++) { + for (at = len-2; at >= 0; at--) { if (str[at] == '@' && str[at+1] == '{') { reflog_len = (len-1) - (at+2); len = at; @@ -324,6 +349,16 @@ static int get_sha1_basic(const char *str, int len, unsigned char *sha1) return -1; if (!len && reflog_len) { + struct strbuf buf = STRBUF_INIT; + int ret; + /* try the @{-N} syntax for n-th checkout */ + ret = interpret_nth_last_branch(str+at, &buf); + if (ret > 0) { + /* substitute this branch name and restart */ + return get_sha1_1(buf.buf, buf.len, sha1); + } else if (ret == 0) { + return -1; + } /* allow "@{...}" to mean the current branch reflog */ refs_found = dwim_ref("HEAD", 4, sha1, &real_ref); } else if (reflog_len) @@ -379,8 +414,6 @@ static int get_sha1_basic(const char *str, int len, unsigned char *sha1) return 0; } -static int get_sha1_1(const char *name, int len, unsigned char *sha1); - static int get_parent(const char *name, int len, unsigned char *result, int idx) { @@ -674,6 +707,92 @@ static int get_sha1_oneline(const char *prefix, unsigned char *sha1) return retval; } +struct grab_nth_branch_switch_cbdata { + long cnt, alloc; + struct strbuf *buf; +}; + +static int grab_nth_branch_switch(unsigned char *osha1, unsigned char *nsha1, + const char *email, unsigned long timestamp, int tz, + const char *message, void *cb_data) +{ + struct grab_nth_branch_switch_cbdata *cb = cb_data; + const char *match = NULL, *target = NULL; + size_t len; + int nth; + + if (!prefixcmp(message, "checkout: moving from ")) { + match = message + strlen("checkout: moving from "); + target = strstr(match, " to "); + } + + if (!match || !target) + return 0; + + len = target - match; + nth = cb->cnt++ % cb->alloc; + strbuf_reset(&cb->buf[nth]); + strbuf_add(&cb->buf[nth], match, len); + return 0; +} + +/* + * This reads "@{-N}" syntax, finds the name of the Nth previous + * branch we were on, and places the name of the branch in the given + * buf and returns the number of characters parsed if successful. + * + * If the input is not of the accepted format, it returns a negative + * number to signal an error. + * + * If the input was ok but there are not N branch switches in the + * reflog, it returns 0. + */ +int interpret_nth_last_branch(const char *name, struct strbuf *buf) +{ + long nth; + int i, retval; + struct grab_nth_branch_switch_cbdata cb; + const char *brace; + char *num_end; + + if (name[0] != '@' || name[1] != '{' || name[2] != '-') + return -1; + brace = strchr(name, '}'); + if (!brace) + return -1; + nth = strtol(name+3, &num_end, 10); + if (num_end != brace) + return -1; + if (nth <= 0) + return -1; + cb.alloc = nth; + cb.buf = xmalloc(nth * sizeof(struct strbuf)); + for (i = 0; i < nth; i++) + strbuf_init(&cb.buf[i], 20); + cb.cnt = 0; + retval = 0; + for_each_recent_reflog_ent("HEAD", grab_nth_branch_switch, 40960, &cb); + if (cb.cnt < nth) { + cb.cnt = 0; + for (i = 0; i < nth; i++) + strbuf_release(&cb.buf[i]); + for_each_reflog_ent("HEAD", grab_nth_branch_switch, &cb); + } + if (cb.cnt < nth) + goto release_return; + i = cb.cnt % nth; + strbuf_reset(buf); + strbuf_add(buf, cb.buf[i].buf, cb.buf[i].len); + retval = brace-name+1; + +release_return: + for (i = 0; i < nth; i++) + strbuf_release(&cb.buf[i]); + free(cb.buf); + + return retval; +} + /* * This is like "get_sha1_basic()", except it allows "sha1 expressions", * notably "xyz^" for "parent of xyz" |