Fix parsing of @{-1}@{1}

To do that, Git no longer looks forward for the '@{' corresponding to the
closing '}' but backward, and dwim_ref() as well as dwim_log() learnt
about the @{-<N>} notation.

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

diff --git a/sha1_name.c b/sha1_name.c
index d6972f2d6a2fd5af38b9babbacd97c9388962bb4..9d544a26332d14998bdcae0474bb66f1f542a4b4 100644 (file)
--- 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;
 
@@ -294,6 +316,7 @@ int dwim_log(const char *str, int len, unsigned char *sha1, char **log)
                if (!warn_ambiguous_refs)
                        break;
        }
+       free(last_branch);
        return logs_found;
 }
 
@@ -312,7 +335,7 @@ 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 (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;

diff --git a/t/t1505-rev-parse-last.sh b/t/t1505-rev-parse-last.sh
index 1e49dd2c8fb2c21db3ef4f29bdb1c3f63aa0a748..c745ec437205ca564bd90e2e5f776eccf57105b9 100755 (executable)
--- a/t/t1505-rev-parse-last.sh
+++ b/t/t1505-rev-parse-last.sh
@@ -54,7 +54,7 @@ test_expect_success '@{-1}^2 works' '
        test_rev_equivalent side^2 @{-1}^2
 '
 
-test_expect_failure '@{-1}@{1} works' '
+test_expect_success '@{-1}@{1} works' '
        test_rev_equivalent side@{1} @{-1}@{1}
 '