# merge -s ffonly

5 messages from 2008-10-06 to 2008-10-08. Participants: Shawn O. Pearce, Uwe Kleine-König, Andreas Ericsson, Deskin Miller.
Thread: https://gitlist.dev/t/15806

## Shawn O. Pearce, 2008-10-06 23:56

Subject: merge -s ffonly
Message-ID: <20081006235611.GA17662@spearce.org>
URL: https://gitlist.dev/e/20081006235611.GA17662%40spearce.org

```
I really don't care about this feature.  But Randal's whining on
#git made me stop what I was doing and write something that might
turn into it.

Totally untested code.  It might reformat your C:\ drive and install
Windows ME.  Install as $(git --exec-path)/git-merge-ffonly and
call as `git merge -s ffonly`.

If you care about this sort of feature, test it, write tests for it,
make a formal patch, and send it for review.  No, I will not do this
for you.  As I said, I don't care about this as a feature.

--8<--
diff --git a/git-merge-ffonly.sh b/git-merge-ffonly.sh
new file mode 100644
index 0000000..24363b5
--- /dev/null
+++ b/git-merge-ffonly.sh
@@ -0,0 +1,20 @@
+#!/bin/sh
+while test $# -gt 0
+do
+	if test "z$1" = z--
+	then
+		shift
+		break
+	else
+		shift
+	fi
+done
+
+while test $# -gt 0
+do
+	if test -n "$(git rev-list $1..HEAD)"
+	then
+		exit 2
+	fi
+	shift
+done

-- 
Shawn.

```

## Uwe Kleine-König, 2008-10-07 18:58

Subject: [RFC] git rev-contains [Was: merge -s ffonly]
Message-ID: <20081007185815.GA10744@strlen.de>
URL: https://gitlist.dev/e/20081007185815.GA10744%40strlen.de
In-Reply-To: <20081006235611.GA17662@spearce.org>

```
Hello,

> +	if test -n "$(git rev-list $1..HEAD)"
I already wrote similar tests and I wonder if this couldn't be done in a
new builtin command more effectively.  Something like

	git rev-contains HEAD "$1"

.  I expect it to be faster and maybe it prevents a command line
overflow?!  (I remember something like 32000 chars max in a command, but
I could not trigger that with bash.)

Best regards
Uwe

```

## Andreas Ericsson, 2008-10-08 06:18

Subject: Re: [RFC] git rev-contains [Was: merge -s ffonly]
Message-ID: <48EC50C8.4000603@op5.se>
URL: https://gitlist.dev/e/48EC50C8.4000603%40op5.se
In-Reply-To: <20081007185815.GA10744@strlen.de>

```
Uwe Kleine-König wrote:
> Hello,
> 
>> +	if test -n "$(git rev-list $1..HEAD)"
> I already wrote similar tests and I wonder if this couldn't be done in a
> new builtin command more effectively.  Something like
> 
> 	git rev-contains HEAD "$1"
> 
> .  I expect it to be faster and maybe it prevents a command line
> overflow?!  (I remember something like 32000 chars max in a command, but
> I could not trigger that with bash.)
> 

On Linux (well, on my system anyways), it's 128K for arguments and
environment combined.

-- 
Andreas Ericsson                   andreas.ericsson@op5.se
OP5 AB                             www.op5.se
Tel: +46 8-230225                  Fax: +46 8-230231

```

## Deskin Miller, 2008-10-08 14:30

Subject: Re: [RFC] git rev-contains [Was: merge -s ffonly]
Message-ID: <20081008143050.GG3052@riemann.deskinm.fdns.net>
URL: https://gitlist.dev/e/20081008143050.GG3052%40riemann.deskinm.fdns.net
In-Reply-To: <20081007185815.GA10744@strlen.de>

```
On Tue, Oct 07, 2008 at 08:58:15PM +0200, =?ISO-8859-1?Q?Uwe_Kleine-K=F6nig_ wrote:
> > +	if test -n "$(git rev-list $1..HEAD)"
> I already wrote similar tests and I wonder if this couldn't be done in a
> new builtin command more effectively.  Something like
> 
> 	git rev-contains HEAD "$1"
> 
> .  I expect it to be faster and maybe it prevents a command line
> overflow?! [...]
 
I'm not sure this warrants a builtin; seems like test is perfectly capable of
doing what you want:

if test '(' -n "$(git rev-list --max-count=1 $1..HEAD)" ')' -a \
	'(' -z "$(git rev-list --max-count=1 HEAD..$1)" ')'

The second check is needed to ensure that the commits actually have an
ancestor-descendant relationship.  And --max-count means your command line
won't overflow.

Or what about this:

if test "$(git merge-base $1 HEAD)" = "$(git rev-parse $1)"

My $0.02,
Deskin Miller

```

## Uwe Kleine-König, 2008-10-08 15:41

Subject: Re: [RFC] git rev-contains [Was: merge -s ffonly]
Message-ID: <20081008154106.GA18549@strlen.de>
URL: https://gitlist.dev/e/20081008154106.GA18549%40strlen.de
In-Reply-To: <20081008143050.GG3052@riemann.deskinm.fdns.net>

```
Hello Deskin,

On Wed, Oct 08, 2008 at 10:30:50AM -0400, Deskin Miller wrote:
> On Tue, Oct 07, 2008 at 08:58:15PM +0200, =?ISO-8859-1?Q?Uwe_Kleine-K=F6nig_ wrote:
> > > +	if test -n "$(git rev-list $1..HEAD)"
> > I already wrote similar tests and I wonder if this couldn't be done in a
> > new builtin command more effectively.  Something like
> > 
> > 	git rev-contains HEAD "$1"
> > 
> > .  I expect it to be faster and maybe it prevents a command line
> > overflow?! [...]
>  
> I'm not sure this warrants a builtin; seems like test is perfectly capable of
> doing what you want:
> 
> if test '(' -n "$(git rev-list --max-count=1 $1..HEAD)" ')' -a \
> 	'(' -z "$(git rev-list --max-count=1 HEAD..$1)" ')'
> 
> The second check is needed to ensure that the commits actually have an
> ancestor-descendant relationship.
This is needed for the original patch, too, isn't it.

>                                    And --max-count means your command line
> won't overflow.
ah, --max-count is a nice idea.  Topgit could benefit from it.
 
> Or what about this:
> 
> if test "$(git merge-base $1 HEAD)" = "$(git rev-parse $1)"

It's not entirely clear to me, this works in general, because a
merge-base isn't unique.  It should work in this case, though.

Best regards
Uwe

```