debian/patches/submodule-config-ban-submodule-paths-that-start-with-.diff

From 8554768479aae958c5f738ddc95419a19392682a Mon Sep 17 00:00:00 2001
From: Jeff King <peff@peff.net>
Date: Mon, 24 Sep 2018 04:39:55 -0400
Subject: submodule-config: ban submodule paths that start with a dash

commit 273c61496f88c6495b886acb1041fe57965151da upstream.

We recently banned submodule urls that look like
command-line options. This is the matching change to ban
leading-dash paths.

As with the urls, this should not break any use cases that
currently work. Even with our "--" separator passed to
git-clone, git-submodule.sh gets confused. Without the code
portion of this patch, the clone of "-sub" added in t7417
would yield results like:

    /path/to/git-submodule: 410: cd: Illegal option -s
    /path/to/git-submodule: 417: cd: Illegal option -s
    /path/to/git-submodule: 410: cd: Illegal option -s
    /path/to/git-submodule: 417: cd: Illegal option -s
    Fetched in submodule path '-sub', but it did not contain b56243f8f4eb91b2f1f8109452e659f14dd3fbe4. Direct fetching of that commit failed.

Moreover, naively adding such a submodule doesn't work:

  $ git submodule add $url -sub
  The following path is ignored by one of your .gitignore files:
  -sub

even though there is no such ignore pattern (the test script
hacks around this with a well-placed "git mv").

Unlike leading-dash urls, though, it's possible that such a
path _could_ be useful if we eventually made it work. So
this commit should be seen not as recommending a particular
policy, but rather temporarily closing off a broken and
possibly dangerous code-path. We may revisit this decision
later.

There are two minor differences to the tests in t7416 (that
covered urls):

  1. We don't have a "./-sub" escape hatch to make this
     work, since the submodule code expects to be able to
     match canonical index names to the path field (so you
     are free to add submodule config with that path, but we
     would never actually use it, since an index entry would
     never start with "./").

  2. After this patch, cloning actually succeeds. Since we
     ignore the submodule.*.path value, we fail to find a
     config stanza for our submodule at all, and simply
     treat it as inactive. We still check for the "ignoring"
     message.

[jn: the original patch expects 'git clone' to succeed in
 the test because v2.13.0-rc0~10^2~3 (clone: teach
 --recurse-submodules to optionally take a pathspec,
 2017-03-17) makes 'git clone' skip invalid submodules.
 Updated the test to pass in older Git versions where the
 submodule name check makes 'git clone' fail.]

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Signed-off-by: Jonathan Nieder <jrnieder@gmail.com>
---
 submodule-config.c            |  2 ++
 t/t7417-submodule-path-url.sh | 20 ++++++++++++++++++++
 2 files changed, 22 insertions(+)
 create mode 100755 t/t7417-submodule-path-url.sh

diff --git a/submodule-config.c b/submodule-config.c
index 3ea69303f9..3be591783e 100644
--- a/submodule-config.c
+++ b/submodule-config.c
@@ -336,6 +336,8 @@ static int parse_config(const char *var, const char *value, void *data)
 	if (!strcmp(item.buf, "path")) {
 		if (!value)
 			ret = config_error_nonbool(var);
+		else if (looks_like_command_line_option(value))
+			warn_command_line_option(var, value);
 		else if (!me->overwrite && submodule->path)
 			warn_multiple_config(me->commit_sha1, submodule->name,
 					"path");
diff --git a/t/t7417-submodule-path-url.sh b/t/t7417-submodule-path-url.sh
new file mode 100755
index 0000000000..894ed51685
--- /dev/null
+++ b/t/t7417-submodule-path-url.sh
@@ -0,0 +1,20 @@
+#!/bin/sh
+
+test_description='check handling of .gitmodule path with dash'
+. ./test-lib.sh
+
+test_expect_success 'create submodule with dash in path' '
+	git init upstream &&
+	git -C upstream commit --allow-empty -m base &&
+	git submodule add ./upstream sub &&
+	git mv sub ./-sub &&
+	git commit -m submodule
+'
+
+test_expect_success 'clone rejects unprotected dash' '
+	test_when_finished "rm -rf dst" &&
+	test_might_fail git clone --recurse-submodules . dst 2>err &&
+	test_i18ngrep ignoring err
+'
+
+test_done
-- 
2.19.0.605.g01d371f741