[PATCH] contrib/subtree: ensure only one rev is provided

[PATCH] contrib/subtree: ensure only one rev is provided

[Denton Liu]

While looking at the inline help for git-subtree.sh, I noticed that

	git subtree split --prefix=<prefix> <commit...>

was given as an option. However, it only really makes sense to provide
one revision because of the way the commits are forwarded to rev-parse
so this commit changes "<commit...>" to "<commit>" to reflect this. In
addition, it checks the arguments to ensure that only one rev is
provided for all subcommands that accept a commit.

Signed-off-by: Denton Liu <liu.denton@gmail.com>
---
 contrib/subtree/git-subtree.sh | 24 ++++++++++++------------
 1 file changed, 12 insertions(+), 12 deletions(-)

diff --git a/contrib/subtree/git-subtree.sh b/contrib/subtree/git-subtree.sh
index 147201dc6c..868e18b9a1 100755
--- a/contrib/subtree/git-subtree.sh
+++ b/contrib/subtree/git-subtree.sh
@@ -14,7 +14,7 @@ git subtree add   --prefix=<prefix> <repository> <ref>
 git subtree merge --prefix=<prefix> <commit>
 git subtree pull  --prefix=<prefix> <repository> <ref>
 git subtree push  --prefix=<prefix> <repository> <ref>
-git subtree split --prefix=<prefix> <commit...>
+git subtree split --prefix=<prefix> <commit>
 --
 h,help        show the help
 q             quiet
@@ -77,6 +77,12 @@ assert () {
 	fi
 }
 
+ensure_single_rev () {
+	if test $# -ne 1
+	then
+		die "You must provide exactly one revision.  Got: '$@'"
+	fi
+}
 
 while test $# -gt 0
 do
@@ -185,6 +191,7 @@ if test "$command" != "pull" &&
 then
 	revs=$(git rev-parse $default --revs-only "$@") || exit $?
 	dirs=$(git rev-parse --no-revs --no-flags "$@") || exit $?
+	ensure_single_rev $revs
 	if test -n "$dirs"
 	then
 		die "Error: Use --prefix instead of bare filenames."
@@ -716,9 +723,8 @@ cmd_add_repository () {
 }
 
 cmd_add_commit () {
-	revs=$(git rev-parse $default --revs-only "$@") || exit $?
-	set -- $revs
-	rev="$1"
+	rev=$(git rev-parse $default --revs-only "$@") || exit $?
+	ensure_single_rev $rev
 
 	debug "Adding $dir as '$rev'..."
 	git read-tree --prefix="$dir" $rev || exit $?
@@ -817,16 +823,10 @@ cmd_split () {
 }
 
 cmd_merge () {
-	revs=$(git rev-parse $default --revs-only "$@") || exit $?
+	rev=$(git rev-parse $default --revs-only "$@") || exit $?
+	ensure_single_rev $rev
 	ensure_clean
 
-	set -- $revs
-	if test $# -ne 1
-	then
-		die "You must provide exactly one revision.  Got: '$revs'"
-	fi
-	rev="$1"
-
 	if test -n "$squash"
 	then
 		first_split="$(find_latest_squash "$dir")"
-- 
2.20.1.522.g5f42c252e9

Re: [PATCH] contrib/subtree: ensure only one rev is provided

[Junio C Hamano]

Denton Liu <liu.denton@gmail.com> writes:

> @@ -185,6 +191,7 @@ if test "$command" != "pull" &&
>  then
>  	revs=$(git rev-parse $default --revs-only "$@") || exit $?
>  	dirs=$(git rev-parse --no-revs --no-flags "$@") || exit $?
> +	ensure_single_rev $revs

This applies to anything other than pull, add and push, so certainly
'split' is covered here.

> @@ -716,9 +723,8 @@ cmd_add_repository () {
>  }
>  
>  cmd_add_commit () {
> -	revs=$(git rev-parse $default --revs-only "$@") || exit $?
> -	set -- $revs
> -	rev="$1"
> +	rev=$(git rev-parse $default --revs-only "$@") || exit $?
> +	ensure_single_rev $rev

There are two callers of this helper.  cmd_add passes "$@" but it
does so only after making sure there is only one argument that is a
commit, so this conversion is not incorrect.

I am not sure if the other caller is OK, though.  cmd_add_repository
can get more than one revs, and uses the first one as $rev to read
the tree from, expecting that this helper to ignore other ones that
are emitted from 'git rev-parse --revs-only "$@"'.

For that matter, one of the early things cmd_split does is to call
the find_existing_splits helper with $revs, and it seems to be
prepared to be red multiple $revs (it is passed to "git log", so I
would expect that incoming $revs is allowed to specify bottom to
limit the traversal, e.g. "git log maint..master").  The addition of
"ensure_single_rev" we saw in an earlier hunk near ll.191 makes such
call impossible.  I am not a user of subtree, so I do not know if
it is a good change (i.e. making something nonsensical impossible to
do is good, making something useful impossible to do is bad).

> @@ -817,16 +823,10 @@ cmd_split () {
>  }
>  
>  cmd_merge () {
> -	revs=$(git rev-parse $default --revs-only "$@") || exit $?
> +	rev=$(git rev-parse $default --revs-only "$@") || exit $?
> +	ensure_single_rev $rev
>  	ensure_clean
>  
> -	set -- $revs
> -	if test $# -ne 1
> -	then
> -		die "You must provide exactly one revision.  Got: '$revs'"
> -	fi
> -	rev="$1"
> -

This one already was insisting on a single version, so it clearly is
a correct no-op conversion, but wouldn't this have been already
caught upfront where anything other than pull, add and push are
handled?  I do understand if the new call to ensure_single is made
to the other caller of cmd_merge in cmd_pull, though.

>  	if test -n "$squash"
>  	then
>  		first_split="$(find_latest_squash "$dir")"

In any case, I do not use subtree, and the last time I looked at
this script is a long time ago, so take all of the above with a
large grain of salt.

Thanks.

Re: [PATCH] contrib/subtree: ensure only one rev is provided

[Avery Pennarun]

 ]0;joe - On Thu, Feb 7, 2019 at 1:54 PM Junio C Hamano
<gitster@pobox.com> wrote:
> I am not sure if the other caller is OK, though.  cmd_add_repository
> can get more than one revs, and uses the first one as $rev to read
> the tree from, expecting that this helper to ignore other ones that
> are emitted from 'git rev-parse --revs-only "$@"'.
>
> For that matter, one of the early things cmd_split does is to call
> the find_existing_splits helper with $revs, and it seems to be
> prepared to be red multiple $revs (it is passed to "git log", so I
> would expect that incoming $revs is allowed to specify bottom to
> limit the traversal, e.g. "git log maint..master").  The addition of
> "ensure_single_rev" we saw in an earlier hunk near ll.191 makes such
> call impossible.  I am not a user of subtree, so I do not know if
> it is a good change (i.e. making something nonsensical impossible to
> do is good, making something useful impossible to do is bad).

I think this generality is probably not useful and it will probably confuse
people less if we prevent it.  It was just one of those "if you don't have
any better ideas, just let people do whatever complicated thing they want"
approaches I used when I was first writing it and didn't know how people
would end up using it.

> In any case, I do not use subtree, and the last time I looked at
> this script is a long time ago, so take all of the above with a
> large grain of salt.

I don't use it very often either.  To be honest, I've noticed weird
behaviour in the version installed with git 2.11.0 in Debian, so I went back
to my own version at https://github.com/apenwarr/git-subtree.  I've been
meaning to investigate further to see what patch might have happened that
caused it to act weird; maybe it's since been fixed.

But I don't see any major problems with the patch in this thread.

Thanks!

Avery

Re: [PATCH] contrib/subtree: ensure only one rev is provided

[Denton Liu]

On Thu, Feb 07, 2019 at 05:34:38PM -0500, Avery Pennarun wrote:
> But I don't see any major problems with the patch in this thread.
> 
> Thanks!
> 
> Avery

Hi Junio,

If there are no other comments, I think that this patch is ready to be
queued.

Thanks,

Denton

Re: [PATCH] contrib/subtree: ensure only one rev is provided

[Denton Liu]

On Tue, Feb 12, 2019 at 02:00:02AM -0800, Denton Liu wrote:
> On Thu, Feb 07, 2019 at 05:34:38PM -0500, Avery Pennarun wrote:
> > But I don't see any major problems with the patch in this thread.
> > 
> > Thanks!
> > 
> > Avery
> 
> Hi Junio,
> 
> If there are no other comments, I think that this patch is ready to be
> queued.
> 
> Thanks,
> 
> Denton

Hi Junio,

Sorry for the spam but it seems like this patch was dropped. If there
aren't any other comments on the patch, then I think it's ready to be
queued. Patch below for your convenience.

Thanks,

Denton

-- >8 --
Subject: [PATCH] contrib/subtree: ensure only one rev is provided

While looking at the inline help for git-subtree.sh, I noticed that

	git subtree split --prefix=<prefix> <commit...>

was given as an option. However, it only really makes sense to provide
one revision because of the way the commits are forwarded to rev-parse
so change "<commit...>" to "<commit>" to reflect this. In addition,
check the arguments to ensure that only one rev is provided for all
subcommands that accept a commit.

Signed-off-by: Denton Liu <liu.denton@gmail.com>
---
 contrib/subtree/git-subtree.sh | 24 ++++++++++++------------
 1 file changed, 12 insertions(+), 12 deletions(-)

diff --git a/contrib/subtree/git-subtree.sh b/contrib/subtree/git-subtree.sh
index 147201dc6c..868e18b9a1 100755
--- a/contrib/subtree/git-subtree.sh
+++ b/contrib/subtree/git-subtree.sh
@@ -14,7 +14,7 @@ git subtree add   --prefix=<prefix> <repository> <ref>
 git subtree merge --prefix=<prefix> <commit>
 git subtree pull  --prefix=<prefix> <repository> <ref>
 git subtree push  --prefix=<prefix> <repository> <ref>
-git subtree split --prefix=<prefix> <commit...>
+git subtree split --prefix=<prefix> <commit>
 --
 h,help        show the help
 q             quiet
@@ -77,6 +77,12 @@ assert () {
 	fi
 }
 
+ensure_single_rev () {
+	if test $# -ne 1
+	then
+		die "You must provide exactly one revision.  Got: '$@'"
+	fi
+}
 
 while test $# -gt 0
 do
@@ -185,6 +191,7 @@ if test "$command" != "pull" &&
 then
 	revs=$(git rev-parse $default --revs-only "$@") || exit $?
 	dirs=$(git rev-parse --no-revs --no-flags "$@") || exit $?
+	ensure_single_rev $revs
 	if test -n "$dirs"
 	then
 		die "Error: Use --prefix instead of bare filenames."
@@ -716,9 +723,8 @@ cmd_add_repository () {
 }
 
 cmd_add_commit () {
-	revs=$(git rev-parse $default --revs-only "$@") || exit $?
-	set -- $revs
-	rev="$1"
+	rev=$(git rev-parse $default --revs-only "$@") || exit $?
+	ensure_single_rev $rev
 
 	debug "Adding $dir as '$rev'..."
 	git read-tree --prefix="$dir" $rev || exit $?
@@ -817,16 +823,10 @@ cmd_split () {
 }
 
 cmd_merge () {
-	revs=$(git rev-parse $default --revs-only "$@") || exit $?
+	rev=$(git rev-parse $default --revs-only "$@") || exit $?
+	ensure_single_rev $rev
 	ensure_clean
 
-	set -- $revs
-	if test $# -ne 1
-	then
-		die "You must provide exactly one revision.  Got: '$revs'"
-	fi
-	rev="$1"
-
 	if test -n "$squash"
 	then
 		first_split="$(find_latest_squash "$dir")"
-- 
2.20.1.522.g5f42c252e9