From mboxrd@z Thu Jan 1 00:00:00 1970 Path: news.gmane.org!not-for-mail From: Robert Thorpe Newsgroups: gmane.emacs.help Subject: Re: removing white space highlight Date: Sun, 28 Feb 2016 18:09:52 +0000 Message-ID: <87povgvh8v.fsf@robertthorpeconsulting.com> References: <877fhph7vu.fsf@debian.uxu> NNTP-Posting-Host: plane.gmane.org Mime-Version: 1.0 Content-Type: text/plain X-Trace: ger.gmane.org 1456683026 15596 80.91.229.3 (28 Feb 2016 18:10:26 GMT) X-Complaints-To: usenet@ger.gmane.org NNTP-Posting-Date: Sun, 28 Feb 2016 18:10:26 +0000 (UTC) Cc: help-gnu-emacs@gnu.org To: Emanuel Berg Original-X-From: help-gnu-emacs-bounces+geh-help-gnu-emacs=m.gmane.org@gnu.org Sun Feb 28 19:10:16 2016 Return-path: Envelope-to: geh-help-gnu-emacs@m.gmane.org Original-Received: from lists.gnu.org ([208.118.235.17]) by plane.gmane.org with esmtp (Exim 4.69) (envelope-from ) id 1aa5nL-0003q5-Ie for geh-help-gnu-emacs@m.gmane.org; Sun, 28 Feb 2016 19:10:15 +0100 Original-Received: from localhost ([::1]:60099 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1aa5nH-00084R-Hi for geh-help-gnu-emacs@m.gmane.org; Sun, 28 Feb 2016 13:10:11 -0500 Original-Received: from eggs.gnu.org ([2001:4830:134:3::10]:52595) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1aa5n5-00083t-SG for help-gnu-emacs@gnu.org; Sun, 28 Feb 2016 13:10:00 -0500 Original-Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1aa5n1-0007Go-OZ for help-gnu-emacs@gnu.org; Sun, 28 Feb 2016 13:09:59 -0500 Original-Received: from outbound-smtp07.blacknight.com ([46.22.139.12]:45384) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1aa5n1-0007GW-IO for help-gnu-emacs@gnu.org; Sun, 28 Feb 2016 13:09:55 -0500 Original-Received: from mail.blacknight.com (pemlinmail01.blacknight.ie [81.17.254.10]) by outbound-smtp07.blacknight.com (Postfix) with ESMTPS id 1B8F01C14EA for ; Sun, 28 Feb 2016 18:09:54 +0000 (GMT) Original-Received: (qmail 11342 invoked from network); 28 Feb 2016 18:09:53 -0000 Original-Received: from unknown (HELO RTLaptop) (rt@robertthorpeconsulting.com@[93.107.80.235]) by 81.17.254.9 with ESMTPSA (DHE-RSA-AES128-SHA encrypted, authenticated); 28 Feb 2016 18:09:53 -0000 In-Reply-To: <877fhph7vu.fsf@debian.uxu> (message from Emanuel Berg on Sun, 28 Feb 2016 03:43:33 +0100) X-detected-operating-system: by eggs.gnu.org: GNU/Linux 2.2.x-3.x [generic] X-Received-From: 46.22.139.12 X-BeenThere: help-gnu-emacs@gnu.org X-Mailman-Version: 2.1.14 Precedence: list List-Id: Users list for the GNU Emacs text editor List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: help-gnu-emacs-bounces+geh-help-gnu-emacs=m.gmane.org@gnu.org Original-Sender: help-gnu-emacs-bounces+geh-help-gnu-emacs=m.gmane.org@gnu.org Xref: news.gmane.org gmane.emacs.help:109358 Archived-At: Emanuel Berg writes: > Robert Thorpe writes: > >> But, what if Harry just deleted some extraneous >> whitespace from the end of the line? In that case we >> can't be sure when important_parameter was last set. >> It may be very old. > > You can do it to the entire project once (and do > nothing else at that point). Let's say I remove whitespace from the entire project. I then check the project back in. Every line that has whitespace removed is flagged as modified. It's added to the repository with my name, date and a new revision number. So, the problem I've described still occurs. To go back to my previous example $ svn blame nasty.c 103 sally /* important_parameter should be */ 103 sally /* set for modern memory sizes. */ 110 rob int important_parameter = 42; 103 sally Here, I have removed all the whitespace at revision 110. That makes it look as though I set the value of important_parameter then. In fact, it was set much earlier. After a long time (maybe a decade), the vast majority of lines in all the files would have been changed. After that the problem wouldn't arise again, but it's a very high price to pay. Of course, if it were possible to modify the version control program then this would be possible. Doing that is "non-trivial", as they say. > Then add automatic > cleaning upon submission, don't log the cleaning, and > last propagate the correct files to anyone who doesn't > have them. > >> Not all version controls systems have that. > > Apparently not :) You don't understand version control systems. You can't change how they work easily. >> It's also not very well known and tools that use the >> VC system (GUIs and Editors) may not use it. > > The editors don't need it, tho it can be useful for > other purposes (e.g., your own files) and it doesn't > hurt having it there as well. This part of the discussion was about what happens if the version control system has an option to deal with whitespace changes. For example, "-x -b" in Subversion. In a large project, are you going to tell people that they can't use front-ends to version-control? Let's say, for example, that Vim doesn't support those switches. Are you going to say "I'm sorry Vim users, you have to use command line svn." BR, Robert Thorpe