Bug 24564

On Mon, Jan 22, 2001 at 11:24:00PM +0000, Tony Finch wrote:
> 
> >Number:         24564
> >Category:       bin
> >Synopsis:       local ident strings interfere with mergemaster
> >Confidential:   no
> >Severity:       serious
> >Priority:       medium
> >Responsible:    freebsd-bugs
> >State:          open
> >Quarter:        
> >Keywords:       
> >Date-Required:
> >Class:          change-request
> >Submitter-Id:   current-users
> >Arrival-Date:   Mon Jan 22 15:30:02 PST 2001
> >Closed-Date:
> >Last-Modified:
> >Originator:     Tony Finch
> >Release:        FreeBSD 4.2-BETA-20001113 i386
> >Organization:
> Covalent Technologies Inc.
> >Environment:
> 
> FreeBSD hand.dotat.at 4.2-BETA-20001113 FreeBSD 4.2-BETA-20001113 #0: Tue Nov 14 00:42:35 UTC 2000     fanf@hand.dotat.at:/FreeBSD/obj/FreeBSD/releng4/sys/DELL-Latitude-CPx  i386
> 
> >Description:
> 
> Mergemaster has a "non-strict comparison" facility for ignoring
> local changes to files if the cvs idents have not been changed from
> the standard version of the file. This makes mergemaster runs much
> less time-consuming.
> 
> However, if (like me) you keep system configuration files in CVS
> then the ident strings will no longer match exactly, and the benefit
> of non-strict comparisons is lost.
> 
> This problem can be avoided by ignoring extra ident strings in the
> destination file, and instead only checking that all the ident strings
> in the source file are present in the destination file.


Or using a different tag instead of $FreeBSD$, in your local
repository.  In this case mergemaster will do exactly the right
thing :).

It's fairly straightforward to configure a copy of the project's
CVSROOT scripts to do the job.

Joe

On Mon, Jan 22, 2001 at 04:00:02PM -0800, Josef Karthauser wrote:
> The following reply was made to PR bin/24564; it has been noted by GNATS.
> 
> From: Josef Karthauser <joe@tao.org.uk>
> To: Tony Finch <dot@dotat.at>
> Cc: FreeBSD-gnats-submit@FreeBSD.ORG
> Subject: Re: bin/24564: local ident strings interfere with mergemaster
> Date: Mon, 22 Jan 2001 23:52:41 +0000
> 
>  --+g7M9IMkV8truYOl
>  Content-Type: text/plain; charset=us-ascii
>  Content-Disposition: inline
>  Content-Transfer-Encoding: quoted-printable
>  
>  On Mon, Jan 22, 2001 at 11:24:00PM +0000, Tony Finch wrote:
>  >=20
>  > >Number:         24564
>  > >Category:       bin
>  > >Synopsis:       local ident strings interfere with mergemaster
>  > >Originator:     Tony Finch
>  > >Organization:
>  > Covalent Technologies Inc.
>  > >Environment:
>  >=20
>  > FreeBSD hand.dotat.at 4.2-BETA-20001113 FreeBSD 4.2-BETA-20001113 #0: Tue=
>   Nov 14 00:42:35 UTC 2000     fanf@hand.dotat.at:/FreeBSD/obj/FreeBSD/relen=
>  g4/sys/DELL-Latitude-CPx  i386
>  >=20
>  > >Description:
>  >=20
>  > Mergemaster has a "non-strict comparison" facility for ignoring
>  > local changes to files if the cvs idents have not been changed from
>  > the standard version of the file. This makes mergemaster runs much
>  > less time-consuming.
>  >=20
>  > However, if (like me) you keep system configuration files in CVS
>  > then the ident strings will no longer match exactly, and the benefit
>  > of non-strict comparisons is lost.
>  >=20
>  > This problem can be avoided by ignoring extra ident strings in the
>  > destination file, and instead only checking that all the ident strings
>  > in the source file are present in the destination file.
>  
>  Or using a different tag instead of $FreeBSD$, in your local
>  repository.  In this case mergemaster will do exactly the right
>  thing :).
>  
>  It's fairly straightforward to configure a copy of the project's
>  CVSROOT scripts to do the job.

Actually, this is not strictly true.  mergemaster was recently changed
so it does a comparison on *all* CVS $Tags$ for a file, so even going
with the plain vanilla Id tags makes mergemaster complain.

When this was done, I emailed Doug Barton and -hackers about it, and
in Message-ID: <3A07BA12.A3CD8C88@FreeBSD.org> Doug said:

<quote from Doug's email>

Peter Pentchev wrote:
>
> Is there a way to make mergemaster revert to its old behavior - only
> comparing $FreeBSD tags on files which have those?

        Of course there is a way, the question is how likely it is to happen.
:)  You've stated the solution, just take the local tags out for now.
They don't tell you anything that 'cvs status' doesn't already tell you.

        I struggled with this change, because I myself use a CVS repo to store
local mods to config files. One of the goals of the current round of
mergemaster mods is to make the thing more palatable across *BSD
platforms. There were already too many if it's one $Id tag or another
definitions in the old code, and it was going to get bigger. If there is
a great hue and cry over this problem, I'll look at changing it back,
but frankly my inclination is that using 'ident' is going to be the best
solution long term.

</quote from Doug's email>

After which I found out that 'cvs status' does indeed do all I wanted :)

Tony, is this answer enough?  'Cause I do not really think Doug is going
to back out his change, when it does not really need to be backed out or
made configurable..

G'luck,
Peter

-- 
If this sentence were in Chinese, it would say something else.

Josef Karthauser <joe@tao.org.uk> wrote:
>On Mon, Jan 22, 2001 at 11:24:00PM +0000, Tony Finch wrote:
>> 
>> This problem can be avoided by ignoring extra ident strings in the
>> destination file, and instead only checking that all the ident strings
>> in the source file are present in the destination file.
>
>Or using a different tag instead of $FreeBSD$, in your local
>repository.  In this case mergemaster will do exactly the right
>thing :).

No that doesn't work for me. I use $Header$ so that my cvs repository
is maximally portable. In fact I haven't done any configuration of it
beyond `cvs init` and I don't need to do any more than that for a
personal repository.

Tony.
-- 
f.a.n.finch    fanf@covalent.net    dot@dotat.at
"Perhaps on your way home you will pass someone in the dark,
and you will never know it, for they will be from outer space."

Comment 4 Doug Barton 2001-01-28 07:12:30 UTC

State Changed
From-To: open->analyzed


I'll be looking at a different solution for this problem. 

Comment 5 Doug Barton 2001-01-28 07:12:30 UTC

Responsible Changed
From-To: freebsd-bugs->dougb


mm is my responsibility.

There's a bug in the patch I originally submitted (changing the
variable in the loop doesn't propagate out to the wider scope), and
I'm not sure why I didn't find it in testing, but anyway, here's a
diff that works.

Index: mergemaster.sh
===================================================================
RCS file: /home/ncvs/src/usr.sbin/mergemaster/mergemaster.sh,v
retrieving revision 1.6.2.5
diff -u -r1.6.2.5 mergemaster.sh
--- mergemaster.sh	2000/11/09 00:51:38	1.6.2.5
+++ mergemaster.sh	2001/02/08 11:03:44
@@ -671,25 +669,23 @@
 
   case "${STRICT}" in
   '' | [Nn][Oo])
-    # Compare CVS $Id's first so if the file hasn't been modified
-    # local changes will be ignored.
-    # If the files have the same $Id, delete the one in temproot so the
-    # user will have less to wade through if files are left to merge by hand.
+    # Ignore local changes unless the source file has changed, which
+    # we detect by looking at ident strings:
+    # If the destination file has all of the ident strings of the
+    # temproot file, then delete the temproot file so the user will
+    # have less to wade through if files are left to merge by hand.
+    # We allow the user to add local ident strings which are ignored.
     #
-    # Reduce complexity and improve portability by using ident
-    #
-    CVSID1=`ident ${DESTDIR}${COMPFILE#.} 2>&1`
-    CVSID1="${CVSID1#${DESTDIR}}"
-    CVSID2=`ident ${COMPFILE} 2>&1`
-
-    case "${CVSID2}" in
-    *'no id keywords'*)
-      ;;
-    ."${CVSID1}")
+    ident ${COMPFILE} 2>&1 | {
+      read DISCARD_FILENAME
+      while read IDENT_STRING; do
+        echo $IDENT_STRING
+	ident ${DESTDIR}${COMPFILE#.} 2>&1 | fgrep -q "${IDENT_STRING}" || echo no
+      done
+    } | grep -q no || {
       echo " *** Temp ${COMPFILE} and installed have the same CVS Id, deleting"
       rm "${COMPFILE}"
-      ;;
-    esac
+    }
     ;;
   esac

Comment 7 Doug Barton 2001-03-05 20:36:12 UTC

State Changed
From-To: analyzed->closed


A different solution for this problem (namely, return to the 
way CVS $Id strings were used previously) was committed to 
-current and releng_4.