[PATCH] Avoid bug in Solaris xpg4/sed as used in submodule

[Ben Walton <bwalton@artsci.utoronto.ca>]

The sed provided by Solaris in /usr/xpg4/bin has a bug whereby an
unanchored regex using * for zero or more repetitions sees two
separate matches fed to the substitution engine in some cases.

This is evidenced by:

$ for sed in /usr/xpg4/bin/sed /usr/bin/sed /opt/csw/gnu/sed; do \
echo 'ab' | $sed -e 's|[a]*|X|g'; \
done
XXbX
XbX
XbX

This bug was triggered during a git submodule clone operation as
exercised in the setup stage of t5526-fetch-submodules when using the
default SANE_TOOL_PATH for Solaris.  It led to paths such as
..../.. being used in the submodule .git gitdir reference.

As we do not need to handle fully qualfied paths we can make the
regex match 1 or more instead of 0 or more non-/ characters so use
's|[^/]\{1,\}|..|g' instead, which is correctly handled by all tested
sed implementations.  This expression is semantically different than
the original one.  It will not place leading '..' on a fully qualified
path as the original expression did.  None of the paths passed to the
regex relied on this behaviour so changing it shouldn't have negative
impact.

Signed-off-by: Ben Walton <bwalton@artsci.utoronto.ca>
---

For some reason, I thought that using {x,y} range notation wasn't
valid in this scenario, but I think I was mistaken.  It seems to be
widely used elsewhere throughout the code.  I prefer that to the
[^/][^/]* notation and as they're equivalent, I switched to it.

 git-submodule.sh |    5 +++--
 1 files changed, 3 insertions(+), 2 deletions(-)

diff --git a/git-submodule.sh b/git-submodule.sh
index efc86ad..2c18e0c 100755
--- a/git-submodule.sh
+++ b/git-submodule.sh
@@ -167,10 +167,11 @@ module_clone()
 	a=${a%/}
 	b=${b%/}
 
-	rel=$(echo $b | sed -e 's|[^/]*|..|g')
+	# Turn path components into .. 
+	rel=$(echo $b | sed -e 's|[^/]\{1,\}|..|g')
 	echo "gitdir: $rel/$a" >"$path/.git"
 
-	rel=$(echo $a | sed -e 's|[^/]*|..|g')
+	rel=$(echo $a | sed -e 's|[^/]\{1,\}|..|g')
 	(clear_local_git_env; cd "$path" && GIT_WORK_TREE=. git config core.worktree "$rel/$b")
 }
 
-- 
1.7.9