Re: [PATCH] Resurrect diff-tree-helper -R

From: Daniel Jacobowitz <dan@debian.org>
Date: May 1, 2005, 01:47 UTC
Message-ID: <20050501014726.GA15220@nevyn.them.org>
In-Reply-To: <Pine.LNX.4.58.0504301805300.2296@ppc970.osdl.org>

On Sat, Apr 30, 2005 at 06:09:53PM -0700, Linus Torvalds wrote:

Show 13 quoted lines

> So it would be much nicer (I think) if mode changes are handled 
> separately, with a simple separate line before the diff saying
> 
> 	"Mode change: %o->%o %s", oldmode, newmode, path
> 
> and not mess up the diff header. That way, you only see it when it
> actually makes any difference, and it's more readable both for humans
> _and_ machines as a result.
> 
> Normal "patch" will just ignore the extra lines before the diff anyway, so 
> it won't matter there.
> 
> Comments?

It sounds good - but could you efficiently collect them before any diff output? If you have something like this, it'll be easy to read:

Mode change: 644->755 foo.sh Mode change: 644->755 bar.sh

--- ChangeLog +++ ChangeLog

@@ -1,0 +1,1 @@
+New line
--- copyright
+++ copyright
@@ -1,0 +1,1 @@
+New line


But if you generate this then you might as well not generate the mode
lines at all, for all a human looking at the diff is going to notice
them:

--- ChangeLog
+++ ChangeLog
@@ -1,0 +1,1 @@
+New line
Mode change: 644->755 foo.sh
--- copyright
+++ copyright
@@ -1,0 +1,1 @@
+New line
Mode change: 644->755 bar.sh


The latter is how diff does its "Only in" messages.  I never see them
when I'm looking through a diff of any size; only via diffstat, where
they're clearly disambiguated.

-- 
Daniel Jacobowitz
CodeSourcery, LLC