diff --git a/git-codereview/branch.go b/git-codereview/branch.go
index 1f08337..5ba9d35 100644
--- a/git-codereview/branch.go
+++ b/git-codereview/branch.go
@@ -307,22 +307,24 @@
 	return readGerritChange(id)
 }
 
-const minHashLen = 4 // git minimum hash length accepted on command line
-
-// CommitByHash finds a unique pending commit by its hash prefix.
-// It dies if the hash cannot be resolved to a pending commit,
-// using the action ("mail", "submit") in the failure message.
-func (b *Branch) CommitByHash(action, hash string) *Commit {
-	if len(hash) < minHashLen {
-		dief("cannot %s: commit hash %q must be at least %d digits long", action, hash, minHashLen)
+// CommitByRev finds a unique pending commit by its git <rev>.
+// It dies if rev cannot be resolved to a commit or that commit is not
+// pending on b using the action ("mail", "submit") in the failure message.
+func (b *Branch) CommitByRev(action, rev string) *Commit {
+	// Parse rev to a commit hash.
+	hash, err := cmdOutputErr("git", "rev-parse", "--verify", rev+"^{commit}")
+	if err != nil {
+		msg := strings.TrimPrefix(trim(err.Error()), "fatal: ")
+		dief("cannot %s: %s", action, msg)
 	}
+	hash = trim(hash)
+
+	// Check that hash is a pending commit.
 	var c *Commit
 	for _, c1 := range b.Pending() {
-		if strings.HasPrefix(c1.Hash, hash) {
-			if c != nil {
-				dief("cannot %s: commit hash %q is ambiguous in the current branch", action, hash)
-			}
+		if c1.Hash == hash {
 			c = c1
+			break
 		}
 	}
 	if c == nil {
@@ -348,7 +350,7 @@
 		if action == "submit" {
 			extra = " or use submit -i"
 		}
-		dief("cannot %s: multiple changes pending; must specify commit hash on command line%s:%s", action, extra, buf.String())
+		dief("cannot %s: multiple changes pending; must specify commit on command line%s:%s", action, extra, buf.String())
 	}
 	return work[0]
 }
diff --git a/git-codereview/mail.go b/git-codereview/mail.go
index 0354836..c83a5d8 100644
--- a/git-codereview/mail.go
+++ b/git-codereview/mail.go
@@ -25,7 +25,7 @@
 	flags.Var(ccList, "cc", "comma-separated list of people to CC:")
 
 	flags.Usage = func() {
-		fmt.Fprintf(stderr(), "Usage: %s mail %s [-r reviewer,...] [-cc mail,...] [-topic topic] [-trybot] [commit-hash]\n", os.Args[0], globalFlags)
+		fmt.Fprintf(stderr(), "Usage: %s mail %s [-r reviewer,...] [-cc mail,...] [-topic topic] [-trybot] [commit]\n", os.Args[0], globalFlags)
 	}
 	flags.Parse(args)
 	if len(flags.Args()) > 1 {
@@ -37,7 +37,7 @@
 
 	var c *Commit
 	if len(flags.Args()) == 1 {
-		c = b.CommitByHash("mail", flags.Arg(0))
+		c = b.CommitByRev("mail", flags.Arg(0))
 	} else {
 		c = b.DefaultCommit("mail")
 	}
diff --git a/git-codereview/mail_test.go b/git-codereview/mail_test.go
index e615b76..fa006db 100644
--- a/git-codereview/mail_test.go
+++ b/git-codereview/mail_test.go
@@ -54,6 +54,35 @@
 	testMain(t, "mail", "-diff")
 }
 
+func TestMailMultiple(t *testing.T) {
+	gt := newGitTest(t)
+	defer gt.done()
+
+	srv := newGerritServer(t)
+	defer srv.done()
+
+	gt.work(t)
+	gt.work(t)
+	gt.work(t)
+
+	testMainDied(t, "mail")
+	testPrintedStderr(t, "cannot mail: multiple changes pending")
+
+	// Mail first two and test non-HEAD mail.
+	h := CurrentBranch().Pending()[1].ShortHash
+	testMain(t, "mail", "HEAD^")
+	testRan(t,
+		"git push -q origin "+h+":refs/for/master",
+		"git tag -f work.mailed "+h)
+
+	// Mail HEAD.
+	h = CurrentBranch().Pending()[0].ShortHash
+	testMain(t, "mail", "HEAD")
+	testRan(t,
+		"git push -q origin HEAD:refs/for/master",
+		"git tag -f work.mailed "+h)
+}
+
 var reviewerLog = []string{
 	"Fake 1 <r1@fake.com>",
 	"Fake 1 <r1@fake.com>",
diff --git a/git-codereview/review.go b/git-codereview/review.go
index f4db94a..15766ef 100644
--- a/git-codereview/review.go
+++ b/git-codereview/review.go
@@ -77,9 +77,11 @@
 		Every other operation except help also does this,
 		if they are not already installed.
 
-	mail [-f] [-r reviewer,...] [-cc mail,...]
+	mail [-f] [-r reviewer,...] [-cc mail,...] [commit]
 		Upload change commit to the code review server and send mail
 		requesting a code review.
+		If there are multiple commits on this branch, upload commits
+		up to and including the named commit.
 		If -f is specified, upload even if there are staged changes.
 		The -r and -cc flags identify the email addresses of people to
 		do the code review and to be CC'ed about the code review.
@@ -95,7 +97,7 @@
 		If -l is specified, only use locally available information.
 		If -s is specified, show short output.
 
-	submit [-i | commit-hash...]
+	submit [-i | commit...]
 		Push the pending change to the Gerrit server and tell Gerrit to
 		submit it to the master branch.
 
diff --git a/git-codereview/submit.go b/git-codereview/submit.go
index 809bbe7..d163914 100644
--- a/git-codereview/submit.go
+++ b/git-codereview/submit.go
@@ -18,7 +18,7 @@
 	var interactive bool
 	flags.BoolVar(&interactive, "i", false, "interactively select commits to submit")
 	flags.Usage = func() {
-		fmt.Fprintf(stderr(), "Usage: %s submit %s [-i | commit-hash...]\n", os.Args[0], globalFlags)
+		fmt.Fprintf(stderr(), "Usage: %s submit %s [-i | commit...]\n", os.Args[0], globalFlags)
 	}
 	flags.Parse(args)
 	if interactive && flags.NArg() > 0 {
@@ -35,11 +35,11 @@
 			return
 		}
 		for _, hash := range hashes {
-			cs = append(cs, b.CommitByHash("submit", hash))
+			cs = append(cs, b.CommitByRev("submit", hash))
 		}
 	} else if args := flags.Args(); len(args) >= 1 {
 		for _, arg := range args {
-			cs = append(cs, b.CommitByHash("submit", arg))
+			cs = append(cs, b.CommitByRev("submit", arg))
 		}
 	} else {
 		cs = append(cs, b.DefaultCommit("submit"))
diff --git a/git-codereview/submit_test.go b/git-codereview/submit_test.go
index ed6ddc2..29111fc 100644
--- a/git-codereview/submit_test.go
+++ b/git-codereview/submit_test.go
@@ -177,6 +177,17 @@
 	testMain(t, "submit", cl1.CurrentRevision, cl2.CurrentRevision)
 }
 
+func TestSubmitMultipleNamed(t *testing.T) {
+	gt := newGitTest(t)
+	defer gt.done()
+
+	srv := newGerritServer(t)
+	defer srv.done()
+
+	_, _ = testSubmitMultiple(t, gt, srv)
+	testMain(t, "submit", "HEAD^", "HEAD")
+}
+
 func TestSubmitInteractive(t *testing.T) {
 	if runtime.GOOS == "windows" {
 		t.Skip("see golang.org/issue/13406")