sha1_name: reorganize get_sha1_basic()

diff --git a/sha1_name.c b/sha1_name.c
index c50630a3ea793e0cfd2510b8813129a1685428f4..45b89d9df00de3c31a39a74a0cc0e635b0095cbc 100644 (file)
--- a/sha1_name.c
+++ b/sha1_name.c
@@ -431,13 +431,14 @@ static inline int upstream_mark(const char *string, int len)
 }
 
 static int get_sha1_1(const char *name, int len, unsigned char *sha1, unsigned lookup_flags);
+static int interpret_nth_prior_checkout(const char *name, struct strbuf *buf);
 
 static int get_sha1_basic(const char *str, int len, unsigned char *sha1)
 {
        static const char *warn_msg = "refname '%.*s' is ambiguous.";
        char *real_ref = NULL;
        int refs_found = 0;
-       int at, reflog_len;
+       int at, reflog_len, nth_prior = 0;
 
        if (len == 40 && !get_sha1_hex(str, sha1))
                return 0;
@@ -445,8 +446,12 @@ static int get_sha1_basic(const char *str, int len, unsigned char *sha1)
        /* basic@{time or number or -number} format to query ref-log */
        reflog_len = at = 0;
        if (len && str[len-1] == '}') {
-               for (at = len-2; at >= 0; at--) {
+               for (at = len-4; at >= 0; at--) {
                        if (str[at] == '@' && str[at+1] == '{') {
+                               if (at == 0 && str[2] == '-') {
+                                       nth_prior = 1;
+                                       continue;
+                               }
                                if (!upstream_mark(str + at, len - at)) {
                                        reflog_len = (len-1) - (at+2);
                                        len = at;
@@ -460,20 +465,22 @@ static int get_sha1_basic(const char *str, int len, unsigned char *sha1)
        if (len && ambiguous_path(str, len))
                return -1;
 
-       if (!len && reflog_len) {
+       if (nth_prior) {
                struct strbuf buf = STRBUF_INIT;
-               int ret;
-               /* try the @{-N} syntax for n-th checkout */
-               ret = interpret_branch_name(str+at, &buf);
-               if (ret > 0) {
-                       /* substitute this branch name and restart */
-                       return get_sha1_1(buf.buf, buf.len, sha1, 0);
-               } else if (ret == 0) {
-                       return -1;
+               int detached;
+
+               if (interpret_nth_prior_checkout(str, &buf) > 0) {
+                       detached = (buf.len == 40 && !get_sha1_hex(buf.buf, sha1));
+                       strbuf_release(&buf);
+                       if (detached)
+                               return 0;
                }
+       }
+
+       if (!len && reflog_len)
                /* allow "@{...}" to mean the current branch reflog */
                refs_found = dwim_ref("HEAD", 4, sha1, &real_ref);
-       } else if (reflog_len)
+       else if (reflog_len)
                refs_found = dwim_log(str, len, sha1, &real_ref);
        else
                refs_found = dwim_ref(str, len, sha1, &real_ref);
@@ -594,7 +601,7 @@ struct object *peel_to_type(const char *name, int namelen,
        while (1) {
                if (!o || (!o->parsed && !parse_object(o->sha1)))
                        return NULL;
-               if (o->type == expected_type)
+               if (expected_type == OBJ_ANY || o->type == expected_type)
                        return o;
                if (o->type == OBJ_TAG)
                        o = ((struct tag*) o)->tagged;
@@ -645,6 +652,8 @@ static int peel_onion(const char *name, int len, unsigned char *sha1)
                expected_type = OBJ_TREE;
        else if (!strncmp(blob_type, sp, 4) && sp[4] == '}')
                expected_type = OBJ_BLOB;
+       else if (!prefixcmp(sp, "object}"))
+               expected_type = OBJ_ANY;
        else if (sp[0] == '}')
                expected_type = OBJ_NONE;
        else if (sp[0] == '/')
@@ -654,6 +663,8 @@ static int peel_onion(const char *name, int len, unsigned char *sha1)
 
        if (expected_type == OBJ_COMMIT)
                lookup_flags = GET_SHA1_COMMITTISH;
+       else if (expected_type == OBJ_TREE)
+               lookup_flags = GET_SHA1_TREEISH;
 
        if (get_sha1_1(name, sp - name - 2, outer, lookup_flags))
                return -1;
@@ -856,8 +867,8 @@ static int get_sha1_oneline(const char *prefix, unsigned char *sha1,
 }
 
 struct grab_nth_branch_switch_cbdata {
-       long cnt, alloc;
-       struct strbuf *buf;
+       int remaining;
+       struct strbuf buf;
 };
 
 static int grab_nth_branch_switch(unsigned char *osha1, unsigned char *nsha1,
@@ -867,7 +878,6 @@ static int grab_nth_branch_switch(unsigned char *osha1, unsigned char *nsha1,
        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 ");
@@ -876,11 +886,12 @@ static int grab_nth_branch_switch(unsigned char *osha1, unsigned char *nsha1,
 
        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);
+       if (--(cb->remaining) == 0) {
+               len = target - match;
+               strbuf_reset(&cb->buf);
+               strbuf_add(&cb->buf, match, len);
+               return 1; /* we are done */
+       }
        return 0;
 }
 
@@ -891,7 +902,7 @@ static int grab_nth_branch_switch(unsigned char *osha1, unsigned char *nsha1,
 static int interpret_nth_prior_checkout(const char *name, struct strbuf *buf)
 {
        long nth;
-       int i, retval;
+       int retval;
        struct grab_nth_branch_switch_cbdata cb;
        const char *brace;
        char *num_end;
@@ -901,34 +912,22 @@ static int interpret_nth_prior_checkout(const char *name, struct strbuf *buf)
        brace = strchr(name, '}');
        if (!brace)
                return -1;
-       nth = strtol(name+3, &num_end, 10);
+       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;
+       cb.remaining = nth;
+       strbuf_init(&cb.buf, 20);
+
        retval = 0;
-       for_each_recent_reflog_ent("HEAD", grab_nth_branch_switch, 40960, &cb);
-       if (cb.cnt < nth) {
-               cb.cnt = 0;
-               for_each_reflog_ent("HEAD", grab_nth_branch_switch, &cb);
+       if (0 < for_each_reflog_ent_reverse("HEAD", grab_nth_branch_switch, &cb)) {
+               strbuf_reset(buf);
+               strbuf_add(buf, cb.buf.buf, cb.buf.len);
+               retval = brace - name + 1;
        }
-       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);
 
+       strbuf_release(&cb.buf);
        return retval;
 }