Re: [PATCH] git-new-workdir: add windows compatibility

Daniel Smith [off-list ref] writes:

When running on Windows in MinGW, creating symbolic links via ln always
failed.

Using mklink instead of ln is the recommended method of creating links on
Windows:
http://stackoverflow.com/questions/18641864/git-bash-shell-fails-to-create-symbolic-links

Script now branches on Windows to use mklink. This change should not affect
unix systems.

Signed-off-by: Daniel Smith <redacted>

Has been tested on Windows 8.1 and OS X Yosemite.
---

Swap the "Has been tested..." and "Signed-off-by:" lines.

I'll defer to Windows folks if "mklink" is a sensible thing to use
or not; I have no first-hand experience with Windows, but only heard
that links are for admin user only or something like that, so I want
to hear from people whose judgement on Windows matters I trust.

+iswindows () {
+ [[ -n "$WINDIR" ]];
+}

Please don't add unnecessary bash-isms.  We have kept this script
usable without stepping out of POSIX.

	test -n "$WINDIR"

-git_dir=$(cd "$git_dir" && pwd) || exit 1
+if iswindows
+then
+ git_dir=$(cd "$git_dir"; cmd.exe /c cd) || exit 1
+else
+ git_dir=$(cd "$git_dir" && pwd) || exit 1
+fi

Indentation of lines inside a new block is done with one more level
of HT in our scripts, not with just one SP.

- ln -s "$git_dir/$x" "$new_workdir/.git/$x" || failed
+ if iswindows
+ then

Move these into a helper shell function, starting from here...

+ if test -d "$git_dir/$x"
+ then
+ # create directory symbolic link
+ isdir="/d"
+ fi
+ # convert path separator to backslash
+ targetPath=$(sed -e 's#^J:##' -e 's#/#\\#g' <<< "$git_dir/$x")
+ cmd.exe /c "mklink $isdir \"$new_workdir/.git/$x\" \"$targetPath\"" || failed

... up to here.  Also a few points about these new lines:

 * Use indentation when doing nested if/then/if/then/fi/fi block,
   i.e.

	if isWindows
        then
		if test -d "..."
                then
			isdir=/d
                fi
                target=..
                cmd.exe /c ...
	fi

 * "<<<" is a bash-ism, isn't it?

 * Use of "#" as s/// separator, when slash is not involved, looks
   ugly and makes it harder to read.

 * Is "J:" drive something special (unlike C: or D: drives)?

 * Can computation of targetPath fail?  IOW, shouldn't that line end
   with &&?

 * Share || failed between this part and POSIX part, i.e.

	if isWindows
        then
		ln_s_win "$new_workdir" "$x"
	else
		ln -s "$git_dir/$x" "$new_workdir'.git/$x"
	fi || failed

   where ln_s_win would be the "helper shell function" I suggested.

	ln_s_win () {
		if test -d "$git_dir/$2"
		then
                	isdir=/d
		fi
                target=$(printf "%s" "$git_dir/$2" | sed -e "...") &&
		cmd.exe /c "mklink $isdir ..."
	}

+ else
+ ln -s "$git_dir/$x" "$new_workdir/.git/$x" || failed
+ fi
 done

 # commands below this are run in the context of the new workdir

Thanks.