Merge branch 'dg/subtree-fixes'

contrib/subtree updates, but here are only the ones that looked
ready.  The remainder of the patches will have another day.

* dg/subtree-fixes:
  contrib/subtree: make the manual directory if needed
  contrib/subtree: honor DESTDIR
  contrib/subtree: fix synopsis
  contrib/subtree: better error handling for 'subtree add'
  contrib/subtree: use %B for split subject/body
  contrib/subtree: remove test number comments

contrib/subtree/Makefile

@@ -30,12 +30,13 @@ $(GIT_SUBTREE): $(GIT_SUBTREE_SH)
 doc: $(GIT_SUBTREE_DOC)
 
 install: $(GIT_SUBTREE)
-	$(INSTALL) -m 755 $(GIT_SUBTREE) $(libexecdir)
+	$(INSTALL) -m 755 $(GIT_SUBTREE) $(DESTDIR)$(libexecdir)
 
 install-doc: install-man
 
 install-man: $(GIT_SUBTREE_DOC)
-	$(INSTALL) -m 644 $^ $(man1dir)
+	$(INSTALL) -d -m 755 $(DESTDIR)$(man1dir)
+	$(INSTALL) -m 644 $^ $(DESTDIR)$(man1dir)
 
 $(GIT_SUBTREE_DOC): $(GIT_SUBTREE_XML)
 	xmlto -m $(MANPAGE_NORMAL_XSL)  man $^

contrib/subtree/git-subtree.sh

@@ -9,6 +9,7 @@ if [ $# -eq 0 ]; then
 fi
 OPTS_SPEC="\
 git subtree add   --prefix=<prefix> <commit>
+git subtree add   --prefix=<prefix> <repository> <commit>
 git subtree merge --prefix=<prefix> <commit>
 git subtree pull  --prefix=<prefix> <repository> <refspec...>
 git subtree push  --prefix=<prefix> <repository> <refspec...>
@@ -296,7 +297,7 @@ copy_commit()
 	# We're going to set some environment vars here, so
 	# do it in a subshell to get rid of them safely later
 	debug copy_commit "{$1}" "{$2}" "{$3}"
-	git log -1 --pretty=format:'%an%n%ae%n%ad%n%cn%n%ce%n%cd%n%s%n%n%b' "$1" |
+	git log -1 --pretty=format:'%an%n%ae%n%ad%n%cn%n%ce%n%cd%n%B' "$1" |
 	(
 		read GIT_AUTHOR_NAME
 		read GIT_AUTHOR_EMAIL
@@ -497,12 +498,23 @@ cmd_add()
 	ensure_clean
 
 	if [ $# -eq 1 ]; then
-		"cmd_add_commit" "$@"
+	    git rev-parse -q --verify "$1^{commit}" >/dev/null ||
+	    die "'$1' does not refer to a commit"
+
+	    "cmd_add_commit" "$@"
 	elif [ $# -eq 2 ]; then
-		"cmd_add_repository" "$@"
+	    # Technically we could accept a refspec here but we're
+	    # just going to turn around and add FETCH_HEAD under the
+	    # specified directory.  Allowing a refspec might be
+	    # misleading because we won't do anything with any other
+	    # branches fetched via the refspec.
+	    git rev-parse -q --verify "$2^{commit}" >/dev/null ||
+	    die "'$2' does not refer to a commit"
+
+	    "cmd_add_repository" "$@"
 	else
 	    say "error: parameters were '$@'"
-	    die "Provide either a refspec or a repository and refspec."
+	    die "Provide either a commit or a repository and commit."
 	fi
 }
 

contrib/subtree/git-subtree.txt

@@ -9,7 +9,8 @@ git-subtree - Merge subtrees together and split repository into subtrees
 SYNOPSIS
 --------
 [verse]
-'git subtree' add   -P <prefix> <commit>
+'git subtree' add   -P <prefix> <refspec>
+'git subtree' add   -P <prefix> <repository> <refspec>
 'git subtree' pull  -P <prefix> <repository> <refspec...>
 'git subtree' push  -P <prefix> <repository> <refspec...>
 'git subtree' merge -P <prefix> <commit>