get_sha1: support relative path ":path" syntax

Currently :path and ref:path can be used to refer to a specific object
in index or ref respectively. "path" component is absolute path. This
patch allows "path" to be written as "./path" or "../path", which is
relative to user's original cwd.

This does not work in commands for which startup_info is NULL
(i.e. non-builtin ones, it seems none of them needs this anyway).

Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

diff --git a/Documentation/revisions.txt b/Documentation/revisions.txt
index 3d4b79c480e2c84150bee96392ee2dd2a4b7d3ea..8b519d74487ce1089462df8556e76d1829fb82d4 100644 (file)
--- a/Documentation/revisions.txt
+++ b/Documentation/revisions.txt
@@ -121,6 +121,10 @@ the `$GIT_DIR/refs` directory or from the `$GIT_DIR/packed-refs` file.
   ':path' (with an empty part before the colon, e.g. `:README`)
   is a special case of the syntax described next: content
   recorded in the index at the given path.
+  A path starting with './' or '../' is relative to current working directory.
+  The given path will be converted to be relative to working tree's root directory.
+  This is most useful to address a blob or tree from a commit or tree that has
+  the same tree structure with the working tree.
 
 * A colon, optionally followed by a stage number (0 to 3) and a
   colon, followed by a path (e.g. `:0:README`); this names a blob object in the

diff --git a/sha1_name.c b/sha1_name.c
index 484081de82928108a23a714a76ea88693e56bdd1..f918faf5c7e635b1a3ad9e9e423cefabfbac4ead 100644 (file)
--- a/sha1_name.c
+++ b/sha1_name.c
@@ -1046,6 +1046,23 @@ int get_sha1_with_mode_1(const char *name, unsigned char *sha1, unsigned *mode,
        return ret;
 }
 
+static char *resolve_relative_path(const char *rel)
+{
+       if (prefixcmp(rel, "./") && prefixcmp(rel, "../"))
+               return NULL;
+
+       if (!startup_info)
+               die("BUG: startup_info struct is not initialized.");
+
+       if (!is_inside_work_tree())
+               die("relative path syntax can't be used outside working tree.");
+
+       /* die() inside prefix_path() if resolved path is outside worktree */
+       return prefix_path(startup_info->prefix,
+                          startup_info->prefix ? strlen(startup_info->prefix) : 0,
+                          rel);
+}
+
 int get_sha1_with_context_1(const char *name, unsigned char *sha1,
                            struct object_context *oc,
                            int gently, const char *prefix)
@@ -1060,25 +1077,31 @@ int get_sha1_with_context_1(const char *name, unsigned char *sha1,
        if (!ret)
                return ret;
        /* sha1:path --> object name of path in ent sha1
-        * :path -> object name of path in index
+        * :path -> object name of absolute path in index
+        * :./path -> object name of path relative to cwd in index
         * :[0-3]:path -> object name of path in index at stage
         * :/foo -> recent commit matching foo
         */
        if (name[0] == ':') {
                int stage = 0;
                struct cache_entry *ce;
+               char *new_path = NULL;
                int pos;
                if (namelen > 2 && name[1] == '/')
                        return get_sha1_oneline(name + 2, sha1);
                if (namelen < 3 ||
                    name[2] != ':' ||
-                   name[1] < '0' || '3' < name[1])
+                   name[1] < '0' || '3' < name[1]) {
                        cp = name + 1;
+                       new_path = resolve_relative_path(cp);
+                       if (new_path)
+                               cp = new_path;
+               }
                else {
                        stage = name[1] - '0';
                        cp = name + 3;
                }
-               namelen = namelen - (cp - name);
+               namelen = strlen(cp);
 
                strncpy(oc->path, cp,
                        sizeof(oc->path));
@@ -1096,12 +1119,14 @@ int get_sha1_with_context_1(const char *name, unsigned char *sha1,
                                break;
                        if (ce_stage(ce) == stage) {
                                hashcpy(sha1, ce->sha1);
+                               free(new_path);
                                return 0;
                        }
                        pos++;
                }
                if (!gently)
                        diagnose_invalid_index_path(stage, prefix, cp);
+               free(new_path);
                return -1;
        }
        for (cp = name, bracket_depth = 0; *cp; cp++) {
@@ -1122,6 +1147,11 @@ int get_sha1_with_context_1(const char *name, unsigned char *sha1,
                }
                if (!get_sha1_1(name, cp-name, tree_sha1)) {
                        const char *filename = cp+1;
+                       char *new_filename = NULL;
+
+                       new_filename = resolve_relative_path(filename);
+                       if (new_filename)
+                               filename = new_filename;
                        ret = get_tree_entry(tree_sha1, filename, sha1, &oc->mode);
                        if (!gently) {
                                diagnose_invalid_sha1_path(prefix, filename,
@@ -1133,6 +1163,7 @@ int get_sha1_with_context_1(const char *name, unsigned char *sha1,
                                sizeof(oc->path));
                        oc->path[sizeof(oc->path)-1] = '\0';
 
+                       free(new_filename);
                        return ret;
                } else {
                        if (!gently)

diff --git a/t/t1506-rev-parse-diagnosis.sh b/t/t1506-rev-parse-diagnosis.sh
index 0eeeb0e45090661c0576607792ff9b91d096e282..18664702b968102f393be836306a833731790e80 100755 (executable)
--- a/t/t1506-rev-parse-diagnosis.sh
+++ b/t/t1506-rev-parse-diagnosis.sh
@@ -31,6 +31,43 @@ test_expect_success 'correct file objects' '
         test $HASH_file = $(git rev-parse :0:file.txt) )
 '
 
+test_expect_success 'correct relative file objects (0)' '
+       git rev-parse :file.txt >expected &&
+       git rev-parse :./file.txt >result &&
+       test_cmp expected result
+'
+
+test_expect_success 'correct relative file objects (1)' '
+       git rev-parse HEAD:file.txt >expected &&
+       git rev-parse HEAD:./file.txt >result &&
+       test_cmp expected result
+'
+
+test_expect_success 'correct relative file objects (2)' '
+       (
+               cd subdir &&
+               git rev-parse HEAD:../file.txt >result &&
+               test_cmp ../expected result
+       )
+'
+
+test_expect_success 'correct relative file objects (3)' '
+       (
+               cd subdir &&
+               git rev-parse HEAD:../subdir/../file.txt >result &&
+               test_cmp ../expected result
+       )
+'
+
+test_expect_success 'correct relative file objects (4)' '
+       git rev-parse HEAD:subdir/file.txt >expected &&
+       (
+               cd subdir &&
+               git rev-parse HEAD:./file.txt >result &&
+               test_cmp ../expected result
+       )
+'
+
 test_expect_success 'incorrect revision id' '
        test_must_fail git rev-parse foobar:file.txt 2>error &&
        grep "Invalid object name '"'"'foobar'"'"'." error &&
@@ -75,4 +112,29 @@ test_expect_success 'invalid @{n} reference' '
        grep "fatal: Log for [^ ]* only has [0-9][0-9]* entries." error
 '
 
+test_expect_success 'relative path not found' '
+       (
+               cd subdir &&
+               test_must_fail git rev-parse HEAD:./nonexistent.txt 2>error &&
+               grep subdir/nonexistent.txt error
+       )
+'
+
+test_expect_success 'relative path outside worktree' '
+       test_must_fail git rev-parse HEAD:../file.txt >output 2>error &&
+       test -z "$(cat output)" &&
+       grep "outside repository" error
+'
+
+test_expect_success 'relative path when cwd is outside worktree' '
+       test_must_fail git --git-dir=.git --work-tree=subdir rev-parse HEAD:./file.txt >output 2>error &&
+       test -z "$(cat output)" &&
+       grep "relative path syntax can.t be used outside working tree." error
+'
+
+test_expect_success 'relative path when startup_info is NULL' '
+       test_must_fail test-match-trees HEAD:./file.txt HEAD:./file.txt 2>error &&
+       grep "BUG: startup_info struct is not initialized." error
+'
+
 test_done