setup: don't dereference in-tree symlinks for absolute paths

The prefix_path_gently() function currently applies real_path to
everything if given an absolute path, dereferencing symlinks both
outside and inside the work tree.

This causes most high-level functions to misbehave when acting on
symlinks given via absolute paths. For example

	$ git add /dir/repo/symlink

attempts to add the target of the symlink rather than the symlink
itself, which is usually not what the user intends to do.

In order to manipulate symlinks in the work tree using absolute paths,
symlinks should only be dereferenced outside the work tree.

Modify the prefix_path_gently() to first normalize the path in order to
make sure path levels are separated by '/', then pass the result to
'abspath_part_inside_repo' to find the part inside the work tree
(without dereferencing any symlinks inside the work tree).

For absolute paths, prefix_path_gently() did not, nor does now do, any
actual prefixing, hence the result from abspath_part_in_repo() is
returned as-is.

Fixes t0060-82 and t3004-5.

Signed-off-by: Martin Erik Werner <martinerikwerner@gmail.com>
Reviewed-by: Duy Nguyen <pclouds@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

diff --git a/setup.c b/setup.c
index bb8b53190e20f44dfea332536d5453d285aff79b..8295ba6bd85b54089b2d0c564007b25d563877bc 100644 (file)
--- a/setup.c
+++ b/setup.c
@@ -86,11 +86,17 @@ char *prefix_path_gently(const char *prefix, int len,
        const char *orig = path;
        char *sanitized;
        if (is_absolute_path(orig)) {
-               const char *temp = real_path(path);
-               sanitized = xmalloc(len + strlen(temp) + 1);
-               strcpy(sanitized, temp);
+               sanitized = xmalloc(strlen(path) + 1);
                if (remaining_prefix)
                        *remaining_prefix = 0;
+               if (normalize_path_copy_len(sanitized, path, remaining_prefix)) {
+                       free(sanitized);
+                       return NULL;
+               }
+               if (abspath_part_inside_repo(sanitized)) {
+                       free(sanitized);
+                       return NULL;
+               }
        } else {
                sanitized = xmalloc(len + strlen(path) + 1);
                if (len)
@@ -98,26 +104,10 @@ char *prefix_path_gently(const char *prefix, int len,
                strcpy(sanitized + len, path);
                if (remaining_prefix)
                        *remaining_prefix = len;
-       }
-       if (normalize_path_copy_len(sanitized, sanitized, remaining_prefix))
-               goto error_out;
-       if (is_absolute_path(orig)) {
-               size_t root_len, len, total;
-               const char *work_tree = get_git_work_tree();
-               if (!work_tree)
-                       goto error_out;
-               len = strlen(work_tree);
-               root_len = offset_1st_component(work_tree);
-               total = strlen(sanitized) + 1;
-               if (strncmp(sanitized, work_tree, len) ||
-                   (len > root_len && sanitized[len] != '\0' && sanitized[len] != '/')) {
-               error_out:
+               if (normalize_path_copy_len(sanitized, sanitized, remaining_prefix)) {
                        free(sanitized);
                        return NULL;
                }
-               if (sanitized[len] == '/')
-                       len++;
-               memmove(sanitized, sanitized + len, total - len);
        }
        return sanitized;
 }

diff --git a/t/t0060-path-utils.sh b/t/t0060-path-utils.sh
index f8286b1c3f211d49cc8341b979a57f4b2fb16ec4..c0143a0a70b7d3dc213b691aecea6b3fffbc5844 100755 (executable)
--- a/t/t0060-path-utils.sh
+++ b/t/t0060-path-utils.sh
@@ -190,7 +190,7 @@ test_expect_success SYMLINKS 'real path works on symlinks' '
        test "$sym" = "$(test-path-utils real_path "$dir2/syml")"
 '
 
-test_expect_failure SYMLINKS 'prefix_path works with absolute paths to work tree symlinks' '
+test_expect_success SYMLINKS 'prefix_path works with absolute paths to work tree symlinks' '
        ln -s target symlink &&
        test "$(test-path-utils prefix_path prefix "$(pwd)/symlink")" = "symlink"
 '

diff --git a/t/t3004-ls-files-basic.sh b/t/t3004-ls-files-basic.sh
index e20c077e0f7a463160292272d122bae2bc99426c..9c7adbdbe1cd7bf03e9b8f10a75f0acb4f37a5b2 100755 (executable)
--- a/t/t3004-ls-files-basic.sh
+++ b/t/t3004-ls-files-basic.sh
@@ -36,7 +36,7 @@ test_expect_success 'ls-files -h in corrupt repository' '
        test_i18ngrep "[Uu]sage: git ls-files " broken/usage
 '
 
-test_expect_failure SYMLINKS 'ls-files with absolute paths to symlinks' '
+test_expect_success SYMLINKS 'ls-files with absolute paths to symlinks' '
        mkdir subs &&
        ln -s nosuch link &&
        ln -s ../nosuch subs/link &&