[PATCHv3] git-fetch: Split fetch and merge logic

[PATCHv3] git-fetch: Split fetch and merge logic

[Santi Béjar]

It makes git-parse-remote.sh and almost all git-fetch independent
of the merge logic.

git-fetch fetches the branches from the remote and saves this
information in .git/FETCH_FETCHED, and at the end it generates
the file .git/FETCH_HEAD.

The current merge behaviour is unchanged.

Signed-off-by: Santi Béjar <sbejar@gmail.com>
---
Hi *,

 This version removes the behaviour changes.

 Now to rebase this on top of 'jc/fetch' (a branch of 'pu').

 Santi

 git-fetch.sh        |   79 +++++++++++++++++++++++++++++++--------------------
 git-parse-remote.sh |   64 ++++++++++++-----------------------------
 t/t5510-fetch.sh    |   16 ++++++++++
 3 files changed, 83 insertions(+), 76 deletions(-)

diff --git a/git-fetch.sh b/git-fetch.sh
index d230995..637d732 100755
--- a/git-fetch.sh
+++ b/git-fetch.sh
@@ -77,9 +77,9 @@ do
 	shift
 done
 
+origin=$(get_default_remote)
 case "$#" in
 0)
-	origin=$(get_default_remote)
 	test -n "$(get_remote_url ${origin})" ||
 		die "Where do you want to fetch from today?"
 	set x $origin ; shift ;;
@@ -101,6 +101,7 @@ if test "" = "$append"
 then
 	: >"$GIT_DIR/FETCH_HEAD"
 fi
+: >"$GIT_DIR/FETCH_FETCHED"
 
 # Global that is reused later
 ls_remote_result=$(git ls-remote $exec "$remote") ||
@@ -112,10 +113,6 @@ append_fetch_head () {
     remote_name_="$3"
     remote_nick_="$4"
     local_name_="$5"
-    case "$6" in
-    t) not_for_merge_='not-for-merge' ;;
-    '') not_for_merge_= ;;
-    esac
 
     # remote-nick is the URL given on the command line (or a shorthand)
     # remote-name is the $GIT_DIR relative refs/ path we computed
@@ -146,9 +143,7 @@ append_fetch_head () {
     if git-cat-file commit "$head_" >/dev/null 2>&1
     then
 	headc_=$(git-rev-parse --verify "$head_^0") || exit
-	echo "$headc_	$not_for_merge_	$note_" >>"$GIT_DIR/FETCH_HEAD"
-    else
-	echo "$head_	not-for-merge	$note_" >>"$GIT_DIR/FETCH_HEAD"
+	echo "$headc_	$remote_name_:$local_name_	$note_" >>"$GIT_DIR/FETCH_FETCHED"
     fi
 
     update_local_ref "$local_name_" "$head_" "$note_"
@@ -265,7 +260,7 @@ then
 		  git-show-ref --exclude-existing=refs/tags/ |
 	          while read sha1 name
 		  do
-			echo ".${name}:${name}"
+			echo "${name}:${name}"
 		  done` || exit
 	if test "$#" -gt 1
 	then
@@ -288,13 +283,6 @@ fetch_main () {
 
       # These are relative path from $GIT_DIR, typically starting at refs/
       # but may be HEAD
-      if expr "z$ref" : 'z\.' >/dev/null
-      then
-	  not_for_merge=t
-	  ref=$(expr "z$ref" : 'z\.\(.*\)')
-      else
-	  not_for_merge=
-      fi
       if expr "z$ref" : 'z+' >/dev/null
       then
 	  single_force=t
@@ -375,7 +363,7 @@ fetch_main () {
       esac
 
       append_fetch_head "$head" "$remote" \
-	  "$remote_name" "$remote_nick" "$local_name" "$not_for_merge" || exit
+	  "$remote_name" "$remote_nick" "$local_name" || exit
 
   done
 
@@ -418,28 +406,16 @@ fetch_main () {
 	      case "$ref" in
 	      +$remote_name:*)
 		  single_force=t
-		  not_for_merge=
-		  found="$ref"
-		  break ;;
-	      .+$remote_name:*)
-		  single_force=t
-		  not_for_merge=t
-		  found="$ref"
-		  break ;;
-	      .$remote_name:*)
-		  not_for_merge=t
 		  found="$ref"
 		  break ;;
 	      $remote_name:*)
-		  not_for_merge=
 		  found="$ref"
 		  break ;;
 	      esac
 	  done
 	  local_name=$(expr "z$found" : 'z[^:]*:\(.*\)')
 	  append_fetch_head "$sha1" "$remote" \
-		  "$remote_name" "$remote_nick" "$local_name" \
-		  "$not_for_merge" || exit
+		  "$remote_name" "$remote_nick" "$local_name" || exit
         done
       )
     ) || exit ;;
@@ -463,7 +439,7 @@ case "$no_tags$tags" in
 		do
 			git-cat-file -t "$sha1" >/dev/null 2>&1 || continue
 			echo >&2 "Auto-following $name"
-			echo ".${name}:${name}"
+			echo "${name}:${name}"
 		done)
 	esac
 	case "$taglist" in
@@ -491,3 +467,44 @@ case "$orig_head" in
 	fi
 	;;
 esac
+
+# Generate $GIT_DIR/FETCH_HEAD
+case ",$#,$remote_nick," in
+,1,$origin,)
+	curr_branch=$(git-symbolic-ref -q HEAD | sed -e 's|^refs/heads/||')
+	merge_branches=$(git-repo-config \
+		--get-all "branch.${curr_branch}.merge" | sort -u)
+	fetch_branches=$(get_remote_default_refs_for_fetch -n $remote_nick |
+		sed 's/:.*$//g;s/^+//' | sort -u)
+	test "$merge_branches" && test "$fetch_branches" &&
+	merge_branches=$(echo -e "$merge_branches\n$fetch_branches" | sort | uniq -d)
+	[ -z "$merge_branches" ] ||
+	test "$(get_data_source $remote_nick)" = branches && merge_first=yes;;
+,1,$remote,) merge_branches=HEAD;;
+,1,*)merge_first=yes ;;
+*)
+	shift
+	merge_branches=$(for ref; do
+		expr "z$ref" : 'z.*:' >/dev/null || ref="${ref}:"
+		echo "$(expr "z$ref" : 'z\([^:]*\):')"; done);;
+esac
+
+test "$merge_first" = "yes" &&
+test "$(get_remote_default_refs_for_fetch -t $remote_nick)" != "explicit" &&
+merge_branches= && merge_first=
+
+merge_branches=$(canon_refs_list_for_fetch $merge_branches | sed 's/:.*$//g')
+
+cat "$GIT_DIR"/FETCH_FETCHED | while IFS='	' read sha1 ref note ; do
+	remote_branch=$(expr "z$ref" : 'z\([^:]*\):')
+	for merge_branch in $merge_branches ; do
+		[ "$merge_branch" == "$remote_branch" ] &&
+			echo "$sha1		$note" && continue 2
+	done
+	if ! test "$merge_first" || test "$merge_first" == "done" ; then
+		echo "$sha1	not-for-merge	$note"
+	else
+		echo "$sha1		$note"
+		merge_first=done
+	fi
+done >> "$GIT_DIR/FETCH_HEAD"
diff --git a/git-parse-remote.sh b/git-parse-remote.sh
index 5208ee6..691d46c 100755
--- a/git-parse-remote.sh
+++ b/git-parse-remote.sh
@@ -70,8 +70,7 @@ get_remote_default_refs_for_push () {
 	esac
 }
 
-# Called from canon_refs_list_for_fetch -d "$remote", which
-# is called from get_remote_default_refs_for_fetch to grok
+# Called from get_remote_default_refs_for_fetch to grok
 # refspecs that are retrieved from the configuration, but not
 # from get_remote_refs_for_fetch when it deals with refspecs
 # supplied on the command line.  $ls_remote_result has the list
@@ -130,30 +129,6 @@ expand_refs_wildcard () {
 
 # Subroutine to canonicalize remote:local notation.
 canon_refs_list_for_fetch () {
-	# If called from get_remote_default_refs_for_fetch
-	# leave the branches in branch.${curr_branch}.merge alone,
-	# or the first one otherwise; add prefix . to the rest
-	# to prevent the secondary branches to be merged by default.
-	merge_branches=
-	curr_branch=
-	if test "$1" = "-d"
-	then
-		shift ; remote="$1" ; shift
-		set $(expand_refs_wildcard "$remote" "$@")
-		is_explicit="$1"
-		shift
-		if test "$remote" = "$(get_default_remote)"
-		then
-			curr_branch=$(git-symbolic-ref -q HEAD | \
-			    sed -e 's|^refs/heads/||')
-			merge_branches=$(git-config \
-			    --get-all "branch.${curr_branch}.merge")
-		fi
-		if test -z "$merge_branches" && test $is_explicit != explicit
-		then
-			merge_branches=..this.will.never.match.any.ref..
-		fi
-	fi
 	for ref
 	do
 		force=
@@ -166,18 +141,6 @@ canon_refs_list_for_fetch () {
 		expr "z$ref" : 'z.*:' >/dev/null || ref="${ref}:"
 		remote=$(expr "z$ref" : 'z\([^:]*\):')
 		local=$(expr "z$ref" : 'z[^:]*:\(.*\)')
-		dot_prefix=.
-		if test -z "$merge_branches"
-		then
-			merge_branches=$remote
-			dot_prefix=
-		else
-			for merge_branch in $merge_branches
-			do
-			    [ "$remote" = "$merge_branch" ] &&
-			    dot_prefix= && break
-			done
-		fi
 		case "$remote" in
 		'' | HEAD ) remote=HEAD ;;
 		refs/heads/* | refs/tags/* | refs/remotes/*) ;;
@@ -196,32 +159,43 @@ canon_refs_list_for_fetch () {
 		   git-check-ref-format "$local_ref_name" ||
 		   die "* refusing to create funny ref '$local_ref_name' locally"
 		fi
-		echo "${dot_prefix}${force}${remote}:${local}"
+		echo "${force}${remote}:${local}"
 	done
 }
 
 # Returns list of src: (no store), or src:dst (store)
 get_remote_default_refs_for_fetch () {
+	test "$1" == -t && type=yes && shift
+	test "$1" == -n && canon=no && shift
 	data_source=$(get_data_source "$1")
 	case "$data_source" in
 	'')
-		echo "HEAD:" ;;
+		set explicit "HEAD:" ;;
 	config)
-		canon_refs_list_for_fetch -d "$1" \
-			$(git-config --get-all "remote.$1.fetch") ;;
+		set $(expand_refs_wildcard "$1" \
+			$(git-repo-config --get-all "remote.$1.fetch")) ;;
 	branches)
 		remote_branch=$(sed -ne '/#/s/.*#//p' "$GIT_DIR/branches/$1")
 		case "$remote_branch" in '') remote_branch=master ;; esac
-		echo "refs/heads/${remote_branch}:refs/heads/$1"
+		set explicit "refs/heads/${remote_branch}:refs/heads/$1"
 		;;
 	remotes)
-		canon_refs_list_for_fetch -d "$1" $(sed -ne '/^Pull: */{
+		set $(expand_refs_wildcard "$1" $(sed -ne '/^Pull: */{
 						s///p
-					}' "$GIT_DIR/remotes/$1")
+					}' "$GIT_DIR/remotes/$1"))
 		;;
 	*)
 		die "internal error: get-remote-default-ref-for-push $1" ;;
 	esac
+	if test "$type" = yes ; then
+		echo $1
+	elif test "$canon" = no ; then
+		shift
+		for ref ; do echo "$ref" ; done
+	else
+		shift
+		canon_refs_list_for_fetch "$@"
+	fi
 }
 
 get_remote_refs_for_push () {
diff --git a/t/t5510-fetch.sh b/t/t5510-fetch.sh
index 50c6485..0a19a7d 100755
--- a/t/t5510-fetch.sh
+++ b/t/t5510-fetch.sh
@@ -50,6 +50,22 @@ test_expect_success "fetch test" '
 	test "z$mine" = "z$his"
 '
 
+test_expect_success "fetch test fetched" '
+	cd "$D" &&
+	cd three &&
+	git fetch &&
+	test -f .git/refs/heads/two &&
+	test -f .git/refs/heads/one &&
+	master_in_two=`cd ../two && git rev-parse master` &&
+	one_in_two=`cd ../two && git rev-parse one` &&
+	{
+		echo "$master_in_two	refs/heads/master:refs/heads/two"
+		echo "$one_in_two	refs/heads/one:refs/heads/one"
+	} >expected &&
+	cut -f -2 .git/FETCH_FETCHED >actual &&
+	diff expected actual'
+
+
 test_expect_success "fetch test for-merge" '
 	cd "$D" &&
 	cd three &&
-- 
1.5.0.1.576.g78541

Re: [PATCHv3] git-fetch: Split fetch and merge logic

[Junio C Hamano]

Santi Béjar <sbejar@gmail.com> writes:

> It makes git-parse-remote.sh and almost all git-fetch independent
> of the merge logic.
>
> git-fetch fetches the branches from the remote and saves this
> information in .git/FETCH_FETCHED, and at the end it generates
> the file .git/FETCH_HEAD.

I might have some more comments after actually applying this and
reviewing it with wider contexts, but it looks nice overall.

I am wondering if FETCH_FETCHED is purely for internal use by
git-fetch (it appears so), and if so if it is worth trying to do
without the temporary file, but that is a minor detail.

>  git-fetch.sh        |   79 +++++++++++++++++++++++++++++++--------------------
>  git-parse-remote.sh |   64 ++++++++++++-----------------------------
>  t/t5510-fetch.sh    |   16 ++++++++++
>  3 files changed, 83 insertions(+), 76 deletions(-)

Loses more lines than it adds (+16 lines to test does not
count), which is a very good sign.

> diff --git a/git-fetch.sh b/git-fetch.sh
> index d230995..637d732 100755
> --- a/git-fetch.sh
> +++ b/git-fetch.sh
> @@ -491,3 +467,44 @@ case "$orig_head" in
>  	fi
>  	;;
>  esac
> +
> +# Generate $GIT_DIR/FETCH_HEAD
> +case ",$#,$remote_nick," in
> +,1,$origin,)
> +	curr_branch=$(git-symbolic-ref -q HEAD | sed -e 's|^refs/heads/||')
> +	merge_branches=$(git-repo-config \
> +		--get-all "branch.${curr_branch}.merge" | sort -u)

Why "sort -u" (instead of erroring out if the repository is
misconfigured)?

> +	fetch_branches=$(get_remote_default_refs_for_fetch -n $remote_nick |
> +		sed 's/:.*$//g;s/^+//' | sort -u)

GNU sed users do not have problems with this, but I recall that
we had to rewrite our sed scripts not to use multiple commands
concatenated with ';' for portability, like:

	sed -e 's/:.*$//g' -e 's/^+//'

Again why "sort -u"?

> +	test "$merge_branches" && test "$fetch_branches" &&

We probably would want to be defensive by saying "test -n".

> +	merge_branches=$(echo -e "$merge_branches\n$fetch_branches" | sort | uniq -d)

I appreciate the cleverness of the intersection.  However, is
"echo -e" portable?  I think we have avoided it so far (we have
avoided even "echo -n" which is traditionally much more
available).

> +cat "$GIT_DIR"/FETCH_FETCHED | while IFS='	' read sha1 ref note ; do
> +	remote_branch=$(expr "z$ref" : 'z\([^:]*\):')
> +	for merge_branch in $merge_branches ; do
> +		[ "$merge_branch" == "$remote_branch" ] &&
> +			echo "$sha1		$note" && continue 2
> +	done
> +	if ! test "$merge_first" || test "$merge_first" == "done" ; then
> +		echo "$sha1	not-for-merge	$note"
> +	else
> +		echo "$sha1		$note"
> +		merge_first=done
> +	fi
> +done >> "$GIT_DIR/FETCH_HEAD"

You can do:

	while ...
        do
        done < "$GIT_DIR/FETCH_FETCHED"

which is easier on the eye.  

I often see a buggy shell script that expects assignment in a
while loop to survive after the loop finished, when the loop is
on the downstream side of a pipe (e.g. the loop is run in a
subshell so merge_first after this loop is finished will never
be 'done').  You do not use the variable after the loop so your
script is not buggy, but avoiding a pipe into while loop is a
good habit to get into.

> diff --git a/git-parse-remote.sh b/git-parse-remote.sh
> index 5208ee6..691d46c 100755
> --- a/git-parse-remote.sh
> +++ b/git-parse-remote.sh
> @@ -196,32 +159,43 @@ canon_refs_list_for_fetch () {

>  	config)
> -		canon_refs_list_for_fetch -d "$1" \
> -			$(git-config --get-all "remote.$1.fetch") ;;
> +		set $(expand_refs_wildcard "$1" \
> +			$(git-repo-config --get-all "remote.$1.fetch")) ;;

Oops?  It is not buggy but it's better to set an example by
using git-config consistenty.  You have another mention of
repo-config above.

>  	remotes)
> -		canon_refs_list_for_fetch -d "$1" $(sed -ne '/^Pull: */{
> +		set $(expand_refs_wildcard "$1" $(sed -ne '/^Pull: */{
>  						s///p
> -					}' "$GIT_DIR/remotes/$1")
> +					}' "$GIT_DIR/remotes/$1"))

Hmph.  I wonder why the original author did not do '/^Pull: */s///p'...

Re: [PATCHv3] git-fetch: Split fetch and merge logic

[Santi Béjar]

On 2/23/07, Junio C Hamano <junkio@cox.net> wrote:
> Santi Béjar <sbejar@gmail.com> writes:
>
> > It makes git-parse-remote.sh and almost all git-fetch independent
> > of the merge logic.
> >
> > git-fetch fetches the branches from the remote and saves this
> > information in .git/FETCH_FETCHED, and at the end it generates
> > the file .git/FETCH_HEAD.
>
> I might have some more comments after actually applying this and
> reviewing it with wider contexts, but it looks nice overall.

Thanks.

>
> I am wondering if FETCH_FETCHED is purely for internal use by
> git-fetch (it appears so), and if so if it is worth trying to do
> without the temporary file, but that is a minor detail.

Yes, it's purely internal. With "without the temporary file" you mean
to put the content in a variable or removing at the end?

> > diff --git a/git-fetch.sh b/git-fetch.sh
> > index d230995..637d732 100755
> > --- a/git-fetch.sh
> > +++ b/git-fetch.sh
> > @@ -491,3 +467,44 @@ case "$orig_head" in
> >       fi
> >       ;;
> >  esac
> > +
> > +# Generate $GIT_DIR/FETCH_HEAD
> > +case ",$#,$remote_nick," in
> > +,1,$origin,)
> > +     curr_branch=$(git-symbolic-ref -q HEAD | sed -e 's|^refs/heads/||')
> > +     merge_branches=$(git-repo-config \
> > +             --get-all "branch.${curr_branch}.merge" | sort -u)
>
> Why "sort -u" (instead of erroring out if the repository is
> misconfigured)?

It is consistent with the current code and I needed it for the
intersection below. The check could be added later.

>
> > +     fetch_branches=$(get_remote_default_refs_for_fetch -n $remote_nick |
> > +             sed 's/:.*$//g;s/^+//' | sort -u)
>
> GNU sed users do not have problems with this, but I recall that
> we had to rewrite our sed scripts not to use multiple commands
> concatenated with ';' for portability, like:
>
>         sed -e 's/:.*$//g' -e 's/^+//'

OK.

>
> Again why "sort -u"?

For the intersection below. Moreover, it make sense because
remotes.${remote}.fetch could be of the form:

[remote "origin"]
url=...
fetch= refs/heads/master:refs/remotes/origin/master
fetch= refs/heads/*:refs/remotes/origin/*

to have a well defined first refspec. In this case refs/heads/master
appears twice.

>
> > +     test "$merge_branches" && test "$fetch_branches" &&
>
> We probably would want to be defensive by saying "test -n".
>

Ok.

> > +     merge_branches=$(echo -e "$merge_branches\n$fetch_branches" | sort | uniq -d)
>
> I appreciate the cleverness of the intersection.  However, is
> "echo -e" portable?  I think we have avoided it so far (we have
> avoided even "echo -n" which is traditionally much more
> available).

printf '%s\n%s' "$merge_branches" "$fetch_branches"

is OK?

>
> > +cat "$GIT_DIR"/FETCH_FETCHED | while IFS='   ' read sha1 ref note ; do
> > +     remote_branch=$(expr "z$ref" : 'z\([^:]*\):')
> > +     for merge_branch in $merge_branches ; do
> > +             [ "$merge_branch" == "$remote_branch" ] &&
> > +                     echo "$sha1             $note" && continue 2
> > +     done
> > +     if ! test "$merge_first" || test "$merge_first" == "done" ; then
> > +             echo "$sha1     not-for-merge   $note"
> > +     else
> > +             echo "$sha1             $note"
> > +             merge_first=done
> > +     fi
> > +done >> "$GIT_DIR/FETCH_HEAD"
>
> You can do:
>
>         while ...
>         do
>         done < "$GIT_DIR/FETCH_FETCHED"
>
> which is easier on the eye.
>
> I often see a buggy shell script that expects assignment in a
> while loop to survive after the loop finished, when the loop is
> on the downstream side of a pipe (e.g. the loop is run in a
> subshell so merge_first after this loop is finished will never
> be 'done').  You do not use the variable after the loop so your
> script is not buggy, but avoiding a pipe into while loop is a
> good habit to get into.

OK, and thanks for the explanation.

>
> > diff --git a/git-parse-remote.sh b/git-parse-remote.sh
> > index 5208ee6..691d46c 100755
> > --- a/git-parse-remote.sh
> > +++ b/git-parse-remote.sh
> > @@ -196,32 +159,43 @@ canon_refs_list_for_fetch () {
>
> >       config)
> > -             canon_refs_list_for_fetch -d "$1" \
> > -                     $(git-config --get-all "remote.$1.fetch") ;;
> > +             set $(expand_refs_wildcard "$1" \
> > +                     $(git-repo-config --get-all "remote.$1.fetch")) ;;
>
> Oops?  It is not buggy but it's better to set an example by
> using git-config consistenty.  You have another mention of
> repo-config above.

Yes, of course.

>
> >       remotes)
> > -             canon_refs_list_for_fetch -d "$1" $(sed -ne '/^Pull: */{
> > +             set $(expand_refs_wildcard "$1" $(sed -ne '/^Pull: */{
> >                                               s///p
> > -                                     }' "$GIT_DIR/remotes/$1")
> > +                                     }' "$GIT_DIR/remotes/$1"))
>
> Hmph.  I wonder why the original author did not do '/^Pull: */s///p'...

I don't know, I'll do.

Santi

Re: [PATCHv3] git-fetch: Split fetch and merge logic

[Junio C Hamano]

"Santi Béjar" <sbejar@gmail.com> writes:

> On 2/23/07, Junio C Hamano <junkio@cox.net> wrote:
>
>> I am wondering if FETCH_FETCHED is purely for internal use by
>> git-fetch (it appears so), and if so if it is worth trying to do
>> without the temporary file, but that is a minor detail.
>
> Yes, it's purely internal. With "without the temporary file" you mean
> to put the content in a variable or removing at the end?

If a variable suffices that would be quite nice, but it is not a
big deal.  As the script does fair amount of computation in
subprocess, I suspect it may not be worth trying to use variable,
only to get rid of the temporary file.

>> I appreciate the cleverness of the intersection.  However, is
>> "echo -e" portable?  I think we have avoided it so far (we have
>> avoided even "echo -n" which is traditionally much more
>> available).
>
> printf '%s\n%s' "$merge_branches" "$fetch_branches"
>
> is OK?

Yes.  I think printf is what people who rewrote my "echo -n"
have done elsewhere.

Re: [PATCHv3] git-fetch: Split fetch and merge logic

[Junio C Hamano]

Santi Béjar <sbejar@gmail.com> writes:

> It makes git-parse-remote.sh and almost all git-fetch independent
> of the merge logic.
>
> git-fetch fetches the branches from the remote and saves this
> information in .git/FETCH_FETCHED, and at the end it generates
> the file .git/FETCH_HEAD.
>
> The current merge behaviour is unchanged.

I overlooked your earlier huge testcase patch, but I noticed it
does not include any test that fetches an annotated tag that
points at a commit or a non-commit, nor an unannotated tag that
is a tree or a blob.  I am too tired to check them right now,
but are you sure you are not regressing with them?

It is sometimes handy to be able to say:

	$ git fetch git-gui tag spearce-gpg-pub
        $ git cat-file -p FETCH_HEAD

Re: [PATCHv3] git-fetch: Split fetch and merge logic

[Junio C Hamano]

Junio C Hamano <junkio@cox.net> writes:

> Santi Béjar <sbejar@gmail.com> writes:
> ...
>> The current merge behaviour is unchanged.
>
> I overlooked your earlier huge testcase patch, but I noticed it
> does not include any test that fetches an annotated tag that
> points at a commit or a non-commit, nor an unannotated tag that
> is a tree or a blob.

A couple of other things I think the users of information in
FETCH_HEAD rely on need to be checked by the test suite.

 * Automated following of tags when a branch head is fetched.
   When this happens, I think the users (not just git-pull
   script but end users) expect the branch head to be listed
   first in the FETCH_HEAD file, so that:

	$ git fetch git://some.repo/
	$ git show FETCH_HEAD

   gives stable and useful result.

 * When two refs are listed on the command line explicitly, are
   they listed in the order given by the user in the resulting
   FETCH_HEAD file?

	$ git fetch git://some.repo/ one two
	$ git fetch git://some.repo/ two one

   Again, "git show FETCH_HEAD" after that expects the first one
   to show 'one' and the second one 'two'.  Replacing 'fetch'
   with 'pull' in the example would affect the parent order in
   the resulting Octopus.