git: treat "git -C '<path>'" as a no-op when <path> is empty

'git -C ""' unhelpfully dies with error "Cannot change to ''",
whereas the shell treats `cd ""' as a no-op.  Taking the shell's
behavior as a precedent, teach git to treat `-C ""' as a no-op, as
well.

Helped-by: Junio C Hamano <gitster@pobox.com>
Helped-by: Eric Sunshine <sunshine@sunshineco.com>
Signed-off-by: Karthik Nayak <karthik.188@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

diff --git a/git.c b/git.c
index 6b5ae6a2ace7fffdd2ec50ce915ad5dc01a9c7da..fdea1104079d21ea00f408d4fd5fd36fce4b24a8 100644 (file)
--- a/git.c
+++ b/git.c
@@ -204,10 +204,12 @@ static int handle_options(const char ***argv, int *argc, int *envchanged)
                                fprintf(stderr, "No directory given for -C.\n" );
                                usage(git_usage_string);
                        }
                                fprintf(stderr, "No directory given for -C.\n" );
                                usage(git_usage_string);
                        }

-                       if (chdir((*argv)[1]))
-                               die_errno("Cannot change to '%s'", (*argv)[1]);
-                       if (envchanged)
-                               *envchanged = 1;
+                       if ((*argv)[1][0]) {
+                               if (chdir((*argv)[1]))
+                                       die_errno("Cannot change to '%s'", (*argv)[1]);
+                               if (envchanged)
+                                       *envchanged = 1;
+                       }

                        (*argv)++;
                        (*argc)--;
                } else {
                        (*argv)++;
                        (*argc)--;
                } else {

diff --git a/t/t0056-git-C.sh b/t/t0056-git-C.sh
index 99c037703a676dd63e4c2b53ea87601fc2503b88..2630e756dab7322a5360a67766a648a80a5a7222 100755 (executable)
--- a/t/t0056-git-C.sh
+++ b/t/t0056-git-C.sh
@@ -14,6 +14,16 @@ test_expect_success '"git -C <path>" runs git from the directory <path>' '
        test_cmp expected actual
 '
 
        test_cmp expected actual
 '
 

+test_expect_success '"git -C <path>" with an empty <path> is a no-op' '
+       (
+               mkdir -p dir1/subdir &&
+               cd dir1/subdir &&
+               git -C "" rev-parse --show-prefix >actual &&
+               echo subdir/ >expect &&
+               test_cmp expect actual
+       )
+'
+

 test_expect_success 'Multiple -C options: "-C dir1 -C dir2" is equivalent to "-C dir1/dir2"' '
        test_create_repo dir1/dir2 &&
        echo 1 >dir1/dir2/b.txt &&
 test_expect_success 'Multiple -C options: "-C dir1 -C dir2" is equivalent to "-C dir1/dir2"' '
        test_create_repo dir1/dir2 &&
        echo 1 >dir1/dir2/b.txt &&