[PATCH] mergetool: use more conservative temporary filenames

[PATCH] mergetool: use more conservative temporary filenames

[David Aguilar]

Avoid filenames with multiple dots so that overly-picky tools do
not misinterpret their extension.

Previously, foo/bar.ext in the worktree would result in e.g.

	foo/bar.ext.BASE.1234.ext

This can be improved by having only a single .ext and using
underscore instead of dot so that the extension cannot be
misinterpreted.  The resulting path becomes:

	foo/bar_BASE_1234.ext

Suggested-by: Sergio Ferrero <sferrero@ensoftcorp.com>
Signed-off-by: David Aguilar <davvid@gmail.com>
---
 git-mergetool.sh | 14 +++++++++-----
 1 file changed, 9 insertions(+), 5 deletions(-)

diff --git a/git-mergetool.sh b/git-mergetool.sh
index 9a046b7..1f33051 100755
--- a/git-mergetool.sh
+++ b/git-mergetool.sh
@@ -228,11 +228,15 @@ merge_file () {
 		return 1
 	fi
 
-	ext="$$$(expr "$MERGED" : '.*\(\.[^/]*\)$')"
-	BACKUP="./$MERGED.BACKUP.$ext"
-	LOCAL="./$MERGED.LOCAL.$ext"
-	REMOTE="./$MERGED.REMOTE.$ext"
-	BASE="./$MERGED.BASE.$ext"
+	ext=$(expr "$MERGED" : '.*\(\.[^/]*\)$')
+	base=$(basename "$MERGED" "$ext")
+	dir=$(dirname "$MERGED")
+	suffix="$$""$ext"
+
+	BACKUP="$dir/$base"_BACKUP_"$suffix"
+	BASE="$dir/$base"_BASE_"$suffix"
+	LOCAL="$dir/$base"_LOCAL_"$suffix"
+	REMOTE="$dir/$base"_REMOTE_"$suffix"
 
 	base_mode=$(git ls-files -u -- "$MERGED" | awk '{if ($3==1) print $1;}')
 	local_mode=$(git ls-files -u -- "$MERGED" | awk '{if ($3==2) print $1;}')
-- 
2.1.2.337.gd0cf3c1

Re: [PATCH] mergetool: use more conservative temporary filenames

[Junio C Hamano]

David Aguilar <davvid@gmail.com> writes:

> Avoid filenames with multiple dots so that overly-picky tools do
> not misinterpret their extension.
>
> Previously, foo/bar.ext in the worktree would result in e.g.
>
> 	foo/bar.ext.BASE.1234.ext
>
> This can be improved by having only a single .ext and using
> underscore instead of dot so that the extension cannot be
> misinterpreted.  The resulting path becomes:
>
> 	foo/bar_BASE_1234.ext
>
> Suggested-by: Sergio Ferrero <sferrero@ensoftcorp.com>
> Signed-off-by: David Aguilar <davvid@gmail.com>
> ---
>  git-mergetool.sh | 14 +++++++++-----
>  1 file changed, 9 insertions(+), 5 deletions(-)
>
> diff --git a/git-mergetool.sh b/git-mergetool.sh
> index 9a046b7..1f33051 100755
> --- a/git-mergetool.sh
> +++ b/git-mergetool.sh
> @@ -228,11 +228,15 @@ merge_file () {
>  		return 1
>  	fi
>  
> -	ext="$$$(expr "$MERGED" : '.*\(\.[^/]*\)$')"
> -	BACKUP="./$MERGED.BACKUP.$ext"
> -	LOCAL="./$MERGED.LOCAL.$ext"
> -	REMOTE="./$MERGED.REMOTE.$ext"
> -	BASE="./$MERGED.BASE.$ext"
> +	ext=$(expr "$MERGED" : '.*\(\.[^/]*\)$')
> +	base=$(basename "$MERGED" "$ext")
> +	dir=$(dirname "$MERGED")
> +	suffix="$$""$ext"
> +
> +	BACKUP="$dir/$base"_BACKUP_"$suffix"
> +	BASE="$dir/$base"_BASE_"$suffix"
> +	LOCAL="$dir/$base"_LOCAL_"$suffix"
> +	REMOTE="$dir/$base"_REMOTE_"$suffix"

We used to feed "./foo/bar.ext.BASE.1234.ext"; with this patch we
feed "foo/bar_BASE_1234.ext".  

It does make this particular example look prettier, but is the
droppage of "./" intentional and is free of unintended ill side
effects?

We avoid "local" and bash-isms, so I'd prefer to see us not to
introduce new temporary variables unnecessarily.  I think we can at
least do without basename/dirname in this case, perhaps like so:

	if BASE=$(expr "$MERGED" : '\(.*\)\.[^/]*$')
        then
        	ext=$(expr "$MERGED" : '.*\(\.[^/]*\)$')
	else
        	ext= BASE=$MERGED
	fi
        BACKUP="${BASE}_BACKUP_$$$ext"
        LOCAL="${BASE}_LOCAL_$$$ext"
        REMOTE="${BASE}_REMOTE_$$$ext"
        BASE="${BASE}_BASE_$$$ext"
        
But I do not have very strong opinion either way.  I just didn't
want to have to think about the leading "./" ;-)

Re: [PATCH] mergetool: use more conservative temporary filenames

[David Aguilar]

On Thu, Oct 09, 2014 at 11:36:00AM -0700, Junio C Hamano wrote:
> David Aguilar <davvid@gmail.com> writes:
> 
> > Avoid filenames with multiple dots so that overly-picky tools do
> > not misinterpret their extension.
> >
> > Previously, foo/bar.ext in the worktree would result in e.g.
> >
> > 	foo/bar.ext.BASE.1234.ext
> >
> > This can be improved by having only a single .ext and using
> > underscore instead of dot so that the extension cannot be
> > misinterpreted.  The resulting path becomes:
> >
> > 	foo/bar_BASE_1234.ext
> >
> > Suggested-by: Sergio Ferrero <sferrero@ensoftcorp.com>
> > Signed-off-by: David Aguilar <davvid@gmail.com>
> > ---
> >  git-mergetool.sh | 14 +++++++++-----
> >  1 file changed, 9 insertions(+), 5 deletions(-)
> >
> > diff --git a/git-mergetool.sh b/git-mergetool.sh
> > index 9a046b7..1f33051 100755
> > --- a/git-mergetool.sh
> > +++ b/git-mergetool.sh
> > @@ -228,11 +228,15 @@ merge_file () {
> >  		return 1
> >  	fi
> >  
> > -	ext="$$$(expr "$MERGED" : '.*\(\.[^/]*\)$')"
> > -	BACKUP="./$MERGED.BACKUP.$ext"
> > -	LOCAL="./$MERGED.LOCAL.$ext"
> > -	REMOTE="./$MERGED.REMOTE.$ext"
> > -	BASE="./$MERGED.BASE.$ext"
> > +	ext=$(expr "$MERGED" : '.*\(\.[^/]*\)$')
> > +	base=$(basename "$MERGED" "$ext")
> > +	dir=$(dirname "$MERGED")
> > +	suffix="$$""$ext"
> > +
> > +	BACKUP="$dir/$base"_BACKUP_"$suffix"
> > +	BASE="$dir/$base"_BASE_"$suffix"
> > +	LOCAL="$dir/$base"_LOCAL_"$suffix"
> > +	REMOTE="$dir/$base"_REMOTE_"$suffix"
> 
> We used to feed "./foo/bar.ext.BASE.1234.ext"; with this patch we
> feed "foo/bar_BASE_1234.ext".  
> 
> It does make this particular example look prettier, but is the
> droppage of "./" intentional and is free of unintended ill side
> effects?
> 
> We avoid "local" and bash-isms, so I'd prefer to see us not to
> introduce new temporary variables unnecessarily.  I think we can at
> least do without basename/dirname in this case, perhaps like so:
> 
> 	if BASE=$(expr "$MERGED" : '\(.*\)\.[^/]*$')
>         then
>         	ext=$(expr "$MERGED" : '.*\(\.[^/]*\)$')
> 	else
>         	ext= BASE=$MERGED
> 	fi
>         BACKUP="${BASE}_BACKUP_$$$ext"
>         LOCAL="${BASE}_LOCAL_$$$ext"
>         REMOTE="${BASE}_REMOTE_$$$ext"
>         BASE="${BASE}_BASE_$$$ext"

Clever ;-)

> But I do not have very strong opinion either way.  I just didn't
> want to have to think about the leading "./" ;-)

When I first wrote this I thought, "$(dirname foo) == '.', so it should
be okay", but it slipped my mind that $(dirname foo/bar) != "./foo" --
I like this new version better.

The leading ./ shoudln't make a difference but I also don't want
to have to think about it either.  I'll have a v2 patch shortly.
-- 
David

Re: [PATCH] mergetool: use more conservative temporary filenames

[Charles Bailey]

While you have the lid of this section of code, should we consider (optionally?) using a tmpdir to alleviate the eclipse issue where it wants temporary merge files to be the canonical locations for definitions of things that it finds when scanning source files in the project tree?

[Apologies for this email client's long lines.]

Re: [PATCH] mergetool: use more conservative temporary filenames

[David Aguilar]

On Fri, Oct 10, 2014 at 10:07:20AM +0100, Charles Bailey wrote:
> While you have the lid of this section of code, should we
> consider (optionally?) using a tmpdir to alleviate the eclipse
> issue where it wants temporary merge files to be the canonical
> locations for definitions of things that it finds when
> scanning source files in the project tree?

Hiding it behind mergetool.usetmpdir seems like a good idea.

That could be a good follow-up patch.
I don't use eclipse so I wasn't aware that this is an issue.

Thanks,
-- 
David