Merge branch 'maint'

* maint:
  git-bisect: make "start", "good" and "skip" succeed or fail atomically
  git-am: cope better with an empty Subject: line
  Ignore leading empty lines while summarizing merges
  bisect: squelch "fatal: ref HEAD not a symref" misleading message
  builtin-apply: Show a more descriptive error on failure when opening a patch
  Clarify documentation of git-cvsserver, particularly in relation to git-shell

Documentation/git-cvsserver.txt

@@ -110,7 +110,9 @@ cvs -d ":ext;CVS_SERVER=git-cvsserver:user@server/path/repo.git" co <HEAD_name>
 ------
 This has the advantage that it will be saved in your 'CVS/Root' files and
 you don't need to worry about always setting the correct environment
-variable.
+variable.  SSH users restricted to git-shell don't need to override the default
+with CVS_SERVER (and shouldn't) as git-shell understands `cvs` to mean
+git-cvsserver and pretends that the other end runs the real cvs better.
 --
 2. For each repo that you want accessible from CVS you need to edit config in
    the repo and add the following section.
@@ -141,25 +143,29 @@ allowing access over SSH.
         enabled=1
 ------
 --
-3. On the client machine you need to set the following variables.
-   CVSROOT should be set as per normal, but the directory should point at the
-   appropriate git repo. For example:
+3. If you didn't specify the CVSROOT/CVS_SERVER directly in the checkout command,
+   automatically saving it in your 'CVS/Root' files, then you need to set them
+   explicitly in your environment.  CVSROOT should be set as per normal, but the
+   directory should point at the appropriate git repo.  As above, for SSH clients
+   _not_ restricted to git-shell, CVS_SERVER should be set to git-cvsserver.
 +
 --
-For SSH access, CVS_SERVER should be set to git-cvsserver
-
-Example:
-
 ------
      export CVSROOT=:ext:user@server:/var/git/project.git
      export CVS_SERVER=git-cvsserver
 ------
 --
-4. For SSH clients that will make commits, make sure their .bashrc file
-   sets the GIT_AUTHOR and GIT_COMMITTER variables.
+4. For SSH clients that will make commits, make sure their server-side
+   .ssh/environment files (or .bashrc, etc., according to their specific shell)
+   export appropriate values for GIT_AUTHOR_NAME, GIT_AUTHOR_EMAIL,
+   GIT_COMMITTER_NAME, and GIT_COMMITTER_EMAIL.  For SSH clients whose login
+   shell is bash, .bashrc may be a reasonable alternative.
 
 5. Clients should now be able to check out the project. Use the CVS 'module'
-   name to indicate what GIT 'head' you want to check out. Example:
+   name to indicate what GIT 'head' you want to check out.  This also sets the
+   name of your newly checked-out directory, unless you tell it otherwise with
+   `-d <dir_name>`.  For example, this checks out 'master' branch to the
+   `project-master` directory:
 +
 ------
      cvs co -d project-master master

builtin-apply.c

@@ -3117,7 +3117,7 @@ int cmd_apply(int argc, const char **argv, const char *unused_prefix)
 
 		fd = open(arg, O_RDONLY);
 		if (fd < 0)
-			usage(apply_usage);
+			die("can't open patch '%s': %s", arg, strerror(errno));
 		read_stdin = 0;
 		set_default_whitespace_mode(whitespace_option);
 		errs |= apply_patch(fd, arg, inaccurate_eof);

builtin-fmt-merge-msg.c

@@ -201,14 +201,22 @@ static void shortlog(const char *name, unsigned char *sha1,
 			continue;
 
 		bol = strstr(commit->buffer, "\n\n");
+		if (bol) {
+			unsigned char c;
+			do {
+				c = *++bol;
+			} while (isspace(c));
+			if (!c)
+				bol = NULL;
+		}
+
 		if (!bol) {
 			append_to_list(&subjects, xstrdup(sha1_to_hex(
 							commit->object.sha1)),
 					NULL);
 			continue;
 		}
 
-		bol += 2;
 		eol = strchr(bol, '\n');
 		if (eol) {
 			oneline = xmemdupz(bol, eol - bol);

git-am.sh

@@ -107,7 +107,7 @@ It does not apply to blobs recorded in its index."
     # patch did not touch, so recursive ends up canceling them,
     # saying that we reverted all those changes.
 
-    eval GITHEAD_$his_tree='"$SUBJECT"'
+    eval GITHEAD_$his_tree='"$FIRSTLINE"'
     export GITHEAD_$his_tree
     git-merge-recursive $orig_tree -- HEAD $his_tree || {
 	    git rerere
@@ -117,10 +117,6 @@ It does not apply to blobs recorded in its index."
     unset GITHEAD_$his_tree
 }
 
-reread_subject () {
-	git stripspace <"$1" | sed -e 1q
-}
-
 prec=4
 dotest=".dotest"
 sign= utf8=t keep= skip= interactive= resolved= binary= rebasing=
@@ -331,7 +327,11 @@ do
 			echo "Patch is empty.  Was it split wrong?"
 			stop_here $this
 		}
-		git stripspace < "$dotest/msg" > "$dotest/msg-clean"
+		SUBJECT="$(sed -n '/^Subject/ s/Subject: //p' "$dotest/info")"
+		case "$keep_subject" in -k)  SUBJECT="[PATCH] $SUBJECT" ;; esac
+
+		(echo "$SUBJECT" ; echo ; cat "$dotest/msg") |
+			git stripspace > "$dotest/msg-clean"
 		;;
 	esac
 
@@ -347,9 +347,6 @@ do
 
 	export GIT_AUTHOR_NAME GIT_AUTHOR_EMAIL GIT_AUTHOR_DATE
 
-	SUBJECT="$(sed -n '/^Subject/ s/Subject: //p' "$dotest/info")"
-	case "$keep_subject" in -k)  SUBJECT="[PATCH] $SUBJECT" ;; esac
-
 	case "$resume" in
 	'')
 	    if test '' != "$SIGNOFF"
@@ -368,10 +365,8 @@ do
 		ADD_SIGNOFF=
 	    fi
 	    {
-		printf '%s\n' "$SUBJECT"
 		if test -s "$dotest/msg-clean"
 		then
-			echo
 			cat "$dotest/msg-clean"
 		fi
 		if test '' != "$ADD_SIGNOFF"
@@ -388,6 +383,7 @@ do
 			;;
 		esac
 	esac
+	FIRSTLINE=$(head -1 "$dotest/final-commit")
 
 	resume=
 	if test "$interactive" = t
@@ -408,7 +404,7 @@ do
 		[aA]*) action=yes interactive= ;;
 		[nN]*) action=skip ;;
 		[eE]*) git_editor "$dotest/final-commit"
-		       SUBJECT=$(reread_subject "$dotest/final-commit")
+		       FIRSTLINE=$(head -1 "$dotest/final-commit")
 		       action=again ;;
 		[vV]*) action=again
 		       LESS=-S ${PAGER:-less} "$dotest/patch" ;;
@@ -431,7 +427,7 @@ do
 		stop_here $this
 	fi
 
-	printf 'Applying %s\n' "$SUBJECT"
+	printf 'Applying %s\n' "$FIRSTLINE"
 
 	case "$resolved" in
 	'')
@@ -489,7 +485,7 @@ do
 	tree=$(git write-tree) &&
 	parent=$(git rev-parse --verify HEAD) &&
 	commit=$(git commit-tree $tree -p $parent <"$dotest/final-commit") &&
-	git update-ref -m "$GIT_REFLOG_ACTION: $SUBJECT" HEAD $commit $parent ||
+	git update-ref -m "$GIT_REFLOG_ACTION: $FIRSTLINE" HEAD $commit $parent ||
 	stop_here $this
 
 	if test -x "$GIT_DIR"/hooks/post-applypatch

git-bisect.sh

@@ -66,9 +66,10 @@ bisect_start() {
 	# Verify HEAD. If we were bisecting before this, reset to the
 	# top-of-line master first!
 	#
-	head=$(GIT_DIR="$GIT_DIR" git symbolic-ref HEAD) ||
+	head=$(GIT_DIR="$GIT_DIR" git symbolic-ref -q HEAD) ||
 	head=$(GIT_DIR="$GIT_DIR" git rev-parse --verify HEAD) ||
 	die "Bad HEAD - I need a HEAD"
+	start_head=''
 	case "$head" in
 	refs/heads/bisect)
 		if [ -s "$GIT_DIR/BISECT_START" ]; then
@@ -82,7 +83,7 @@ bisect_start() {
 		# This error message should only be triggered by cogito usage,
 		# and cogito users should understand it relates to cg-seek.
 		[ -s "$GIT_DIR/head-name" ] && die "won't bisect on seeked tree"
-		echo "${head#refs/heads/}" >"$GIT_DIR/BISECT_START"
+		start_head="${head#refs/heads/}"
 		;;
 	*)
 		die "Bad HEAD - strange symbolic ref"
@@ -103,6 +104,7 @@ bisect_start() {
 	done
 	orig_args=$(sq "$@")
 	bad_seen=0
+	eval=''
 	while [ $# -gt 0 ]; do
 	    arg="$1"
 	    case "$arg" in
@@ -120,13 +122,15 @@ bisect_start() {
 		0) state='bad' ; bad_seen=1 ;;
 		*) state='good' ;;
 		esac
-		bisect_write "$state" "$rev" 'nolog'
+		eval="$eval bisect_write '$state' '$rev' 'nolog'; "
 		shift
 		;;
 	    esac
 	done
 
 	sq "$@" >"$GIT_DIR/BISECT_NAMES"
+	test -n "$start_head" && echo "$start_head" >"$GIT_DIR/BISECT_START"
+	eval "$eval"
 	echo "git-bisect start$orig_args" >>"$GIT_DIR/BISECT_LOG"
 	bisect_auto_next
 }
@@ -157,12 +161,14 @@ bisect_state() {
 		bisect_write "$state" "$rev" ;;
 	2,bad|*,good|*,skip)
 		shift
+		eval=''
 		for rev in "$@"
 		do
 			sha=$(git rev-parse --verify "$rev^{commit}") ||
 				die "Bad rev input: $rev"
-			bisect_write "$state" "$sha"
-		done ;;
+			eval="$eval bisect_write '$state' '$sha'; "
+		done
+		eval "$eval" ;;
 	*,bad)
 		die "'git bisect bad' can take only one argument." ;;
 	*)

t/t6030-bisect-porcelain.sh

@@ -71,15 +71,20 @@ test_expect_success 'bisect start with one bad and good' '
 	git bisect next
 '
 
-test_expect_success 'bisect good and bad fails if not given only revs' '
+test_expect_success 'bisect fails if given any junk instead of revs' '
 	git bisect reset &&
+	test_must_fail git bisect start foo $HASH1 -- &&
+	test_must_fail git bisect start $HASH4 $HASH1 bar -- &&
+	test -z "$(git for-each-ref "refs/bisect/*")" &&
+	test_must_fail ls .git/BISECT_* &&
 	git bisect start &&
 	test_must_fail git bisect good foo $HASH1 &&
 	test_must_fail git bisect good $HASH1 bar &&
 	test_must_fail git bisect bad frotz &&
 	test_must_fail git bisect bad $HASH3 $HASH4 &&
 	test_must_fail git bisect skip bar $HASH3 &&
 	test_must_fail git bisect skip $HASH1 foo &&
+	test -z "$(git for-each-ref "refs/bisect/*")" &&
 	git bisect good $HASH1 &&
 	git bisect bad $HASH4
 '