diff options
| -rw-r--r-- | Documentation/git-checkout.txt | 4 | ||||
| -rw-r--r-- | Documentation/git-rev-parse.txt | 3 | ||||
| -rw-r--r-- | builtin-checkout.c | 15 | ||||
| -rw-r--r-- | cache.h | 1 | ||||
| -rw-r--r-- | refs.c | 17 | ||||
| -rw-r--r-- | refs.h | 1 | ||||
| -rw-r--r-- | sha1_name.c | 127 | ||||
| -rwxr-xr-x | t/t1505-rev-parse-last.sh | 69 | ||||
| -rwxr-xr-x | t/t2012-checkout-last.sh | 94 |
9 files changed, 324 insertions, 7 deletions
diff --git a/Documentation/git-checkout.txt b/Documentation/git-checkout.txt index 9cd5151..3bccffa 100644 --- a/Documentation/git-checkout.txt +++ b/Documentation/git-checkout.txt @@ -133,6 +133,10 @@ the conflicted merge in the specified paths. + When this parameter names a non-branch (but still a valid commit object), your HEAD becomes 'detached'. ++ +As a special case, the "`@\{-N\}`" syntax for the N-th last branch +checks out the branch (instead of detaching). You may also specify +"`-`" which is synonymous with "`@\{-1\}`". Detached HEAD diff --git a/Documentation/git-rev-parse.txt b/Documentation/git-rev-parse.txt index 2921da3..3ccef2f 100644 --- a/Documentation/git-rev-parse.txt +++ b/Documentation/git-rev-parse.txt @@ -212,6 +212,9 @@ when you run 'git-merge'. reflog of the current branch. For example, if you are on the branch 'blabla', then '@\{1\}' means the same as 'blabla@\{1\}'. +* The special construct '@\{-<n>\}' means the <n>th branch checked out + before the current one. + * A suffix '{caret}' to a revision parameter means the first parent of that commit object. '{caret}<n>' means the <n>th parent (i.e. 'rev{caret}' diff --git a/builtin-checkout.c b/builtin-checkout.c index 6cdb320..20b34ce 100644 --- a/builtin-checkout.c +++ b/builtin-checkout.c @@ -351,8 +351,16 @@ struct branch_info { static void setup_branch_path(struct branch_info *branch) { struct strbuf buf = STRBUF_INIT; - strbuf_addstr(&buf, "refs/heads/"); - strbuf_addstr(&buf, branch->name); + int ret; + + if ((ret = interpret_nth_last_branch(branch->name, &buf)) + && ret == strlen(branch->name)) { + branch->name = xstrdup(buf.buf); + strbuf_splice(&buf, 0, 0, "refs/heads/", 11); + } else { + strbuf_addstr(&buf, "refs/heads/"); + strbuf_addstr(&buf, branch->name); + } branch->path = strbuf_detach(&buf, NULL); } @@ -661,6 +669,9 @@ int cmd_checkout(int argc, const char **argv, const char *prefix) arg = argv[0]; has_dash_dash = (argc > 1) && !strcmp(argv[1], "--"); + if (!strcmp(arg, "-")) + arg = "@{-1}"; + if (get_sha1(arg, rev)) { if (has_dash_dash) /* case (1) */ die("invalid reference: %s", arg); @@ -667,6 +667,7 @@ extern int read_ref(const char *filename, unsigned char *sha1); extern const char *resolve_ref(const char *path, unsigned char *sha1, int, int *); extern int dwim_ref(const char *str, int len, unsigned char *sha1, char **ref); extern int dwim_log(const char *str, int len, unsigned char *sha1, char **ref); +extern int interpret_nth_last_branch(const char *str, struct strbuf *); extern int refname_match(const char *abbrev_name, const char *full_name, const char **rules); extern const char *ref_rev_parse_rules[]; @@ -1453,7 +1453,7 @@ int read_ref_at(const char *ref, unsigned long at_time, int cnt, unsigned char * return 1; } -int for_each_reflog_ent(const char *ref, each_reflog_ent_fn fn, void *cb_data) +int for_each_recent_reflog_ent(const char *ref, each_reflog_ent_fn fn, long ofs, void *cb_data) { const char *logfile; FILE *logfp; @@ -1464,6 +1464,16 @@ int for_each_reflog_ent(const char *ref, each_reflog_ent_fn fn, void *cb_data) logfp = fopen(logfile, "r"); if (!logfp) return -1; + + if (ofs) { + struct stat statbuf; + if (fstat(fileno(logfp), &statbuf) || + statbuf.st_size < ofs || + fseek(logfp, -ofs, SEEK_END) || + fgets(buf, sizeof(buf), logfp)) + return -1; + } + while (fgets(buf, sizeof(buf), logfp)) { unsigned char osha1[20], nsha1[20]; char *email_end, *message; @@ -1497,6 +1507,11 @@ int for_each_reflog_ent(const char *ref, each_reflog_ent_fn fn, void *cb_data) return ret; } +int for_each_reflog_ent(const char *ref, each_reflog_ent_fn fn, void *cb_data) +{ + return for_each_recent_reflog_ent(ref, fn, 0, cb_data); +} + static int do_for_each_reflog(const char *base, each_ref_fn fn, void *cb_data) { DIR *dir = opendir(git_path("logs/%s", base)); @@ -60,6 +60,7 @@ extern int read_ref_at(const char *ref, unsigned long at_time, int cnt, unsigned /* iterate over reflog entries */ typedef int each_reflog_ent_fn(unsigned char *osha1, unsigned char *nsha1, const char *, unsigned long, int, const char *, void *); int for_each_reflog_ent(const char *ref, each_reflog_ent_fn fn, void *cb_data); +int for_each_recent_reflog_ent(const char *ref, each_reflog_ent_fn fn, long, void *cb_data); /* * Calls the specified function for each reflog file until it returns nonzero, diff --git a/sha1_name.c b/sha1_name.c index 722fc35..5d0ac02 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" diff --git a/t/t1505-rev-parse-last.sh b/t/t1505-rev-parse-last.sh new file mode 100755 index 0000000..d709ecf --- /dev/null +++ b/t/t1505-rev-parse-last.sh @@ -0,0 +1,69 @@ +#!/bin/sh + +test_description='test @{-N} syntax' + +. ./test-lib.sh + + +make_commit () { + echo "$1" > "$1" && + git add "$1" && + git commit -m "$1" +} + + +test_expect_success 'setup' ' + + make_commit 1 && + git branch side && + make_commit 2 && + make_commit 3 && + git checkout side && + make_commit 4 && + git merge master && + git checkout master + +' + +# 1 -- 2 -- 3 master +# \ \ +# \ \ +# --- 4 --- 5 side +# +# and 'side' should be the last branch + +test_rev_equivalent () { + + git rev-parse "$1" > expect && + git rev-parse "$2" > output && + test_cmp expect output + +} + +test_expect_success '@{-1} works' ' + test_rev_equivalent side @{-1} +' + +test_expect_success '@{-1}~2 works' ' + test_rev_equivalent side~2 @{-1}~2 +' + +test_expect_success '@{-1}^2 works' ' + test_rev_equivalent side^2 @{-1}^2 +' + +test_expect_success '@{-1}@{1} works' ' + test_rev_equivalent side@{1} @{-1}@{1} +' + +test_expect_success '@{-2} works' ' + test_rev_equivalent master @{-2} +' + +test_expect_success '@{-3} fails' ' + test_must_fail git rev-parse @{-3} +' + +test_done + + diff --git a/t/t2012-checkout-last.sh b/t/t2012-checkout-last.sh new file mode 100755 index 0000000..87b30a2 --- /dev/null +++ b/t/t2012-checkout-last.sh @@ -0,0 +1,94 @@ +#!/bin/sh + +test_description='checkout can switch to last branch' + +. ./test-lib.sh + +test_expect_success 'setup' ' + echo hello >world && + git add world && + git commit -m initial && + git branch other && + echo "hello again" >>world && + git add world && + git commit -m second +' + +test_expect_success '"checkout -" does not work initially' ' + test_must_fail git checkout - +' + +test_expect_success 'first branch switch' ' + git checkout other +' + +test_expect_success '"checkout -" switches back' ' + git checkout - && + test "z$(git symbolic-ref HEAD)" = "zrefs/heads/master" +' + +test_expect_success '"checkout -" switches forth' ' + git checkout - && + test "z$(git symbolic-ref HEAD)" = "zrefs/heads/other" +' + +test_expect_success 'detach HEAD' ' + git checkout $(git rev-parse HEAD) +' + +test_expect_success '"checkout -" attaches again' ' + git checkout - && + test "z$(git symbolic-ref HEAD)" = "zrefs/heads/other" +' + +test_expect_success '"checkout -" detaches again' ' + git checkout - && + test "z$(git rev-parse HEAD)" = "z$(git rev-parse other)" && + test_must_fail git symbolic-ref HEAD +' + +test_expect_success 'more switches' ' + for i in 16 15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 + do + git checkout -b branch$i + done +' + +more_switches () { + for i in 16 15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 + do + git checkout branch$i + done +} + +test_expect_success 'switch to the last' ' + more_switches && + git checkout @{-1} && + test "z$(git symbolic-ref HEAD)" = "zrefs/heads/branch2" +' + +test_expect_success 'switch to second from the last' ' + more_switches && + git checkout @{-2} && + test "z$(git symbolic-ref HEAD)" = "zrefs/heads/branch3" +' + +test_expect_success 'switch to third from the last' ' + more_switches && + git checkout @{-3} && + test "z$(git symbolic-ref HEAD)" = "zrefs/heads/branch4" +' + +test_expect_success 'switch to fourth from the last' ' + more_switches && + git checkout @{-4} && + test "z$(git symbolic-ref HEAD)" = "zrefs/heads/branch5" +' + +test_expect_success 'switch to twelfth from the last' ' + more_switches && + git checkout @{-12} && + test "z$(git symbolic-ref HEAD)" = "zrefs/heads/branch13" +' + +test_done |