git-codereview: update tests for "main" branch default

"git init ." leaves me on "main" now, not "master".
Update tests to expect that, and update the "tracking" message too
(otherwise the tests fail).

Because not all gits agree about the initial branch name,
set it explicitly too in the test.

Fixes #42926.

Change-Id: If3adb3bb53beba9efcd75cad0f081f59fba85fe7
Reviewed-on: https://go-review.googlesource.com/c/review/+/279873
Trust: Russ Cox <rsc@golang.org>
Reviewed-by: Matthew Dempsky <mdempsky@google.com>
Reviewed-by: Austin Clements <austin@google.com>

9 files changed, 90 insertions, 77 deletions

diff --git a/git-codereview/branch_test.go b/git-codereview/branch_test.go
index d5b8a43..438ff39 100644
--- a/git-codereview/branch_test.go
+++ b/git-codereview/branch_test.go
@@ -14,17 +14,17 @@ func TestCurrentBranch(t *testing.T) {
 	gt := newGitTest(t)
 	defer gt.done()
 
-	t.Logf("on master")
-	checkCurrentBranch(t, "master", "origin/master", false, false, "", "")
+	t.Logf("on main")
+	checkCurrentBranch(t, "main", "origin/main", false, false, "", "")
 
 	t.Logf("on newbranch")
 	trun(t, gt.client, "git", "checkout", "--no-track", "-b", "newbranch")
-	checkCurrentBranch(t, "newbranch", "origin/master", true, false, "", "")
+	checkCurrentBranch(t, "newbranch", "origin/main", true, false, "", "")
 
 	t.Logf("making change")
 	write(t, gt.client+"/file", "i made a change", 0644)
 	trun(t, gt.client, "git", "commit", "-a", "-m", "My change line.\n\nChange-Id: I0123456789abcdef0123456789abcdef\n")
-	checkCurrentBranch(t, "newbranch", "origin/master", true, true, "I0123456789abcdef0123456789abcdef", "My change line.")
+	checkCurrentBranch(t, "newbranch", "origin/main", true, true, "I0123456789abcdef0123456789abcdef", "My change line.")
 
 	t.Logf("on dev.branch")
 	trun(t, gt.client, "git", "checkout", "-t", "-b", "dev.branch", "origin/dev.branch")
@@ -73,16 +73,16 @@ func TestLocalBranches(t *testing.T) {
 	gt := newGitTest(t)
 	defer gt.done()
 
-	t.Logf("on master")
-	checkLocalBranches(t, "master")
+	t.Logf("on main")
+	checkLocalBranches(t, "main")
 
 	t.Logf("on dev branch")
 	trun(t, gt.client, "git", "checkout", "-b", "newbranch")
-	checkLocalBranches(t, "master", "newbranch")
+	checkLocalBranches(t, "main", "newbranch")
 
 	t.Logf("detached head mode")
 	trun(t, gt.client, "git", "checkout", "HEAD^0")
-	checkLocalBranches(t, "HEAD", "master", "newbranch")
+	checkLocalBranches(t, "HEAD", "main", "newbranch")
 }
 
 func checkLocalBranches(t *testing.T, want ...string) {
@@ -103,9 +103,9 @@ func TestAmbiguousRevision(t *testing.T) {
 
 	t.Logf("creating file paths that conflict with revision parameters")
 	mkdir(t, gt.client+"/origin")
-	write(t, gt.client+"/origin/master..work", "Uh-Oh! SpaghettiOs", 0644)
+	write(t, gt.client+"/origin/main..work", "Uh-Oh! SpaghettiOs", 0644)
 	mkdir(t, gt.client+"/work..origin")
-	write(t, gt.client+"/work..origin/master", "Be sure to drink your Ovaltine", 0644)
+	write(t, gt.client+"/work..origin/main", "Be sure to drink your Ovaltine", 0644)
 
 	b := CurrentBranch()
 	b.Submitted("I123456789")
@@ -159,12 +159,12 @@ func TestBranchpointMerge(t *testing.T) {
 	gt := newGitTest(t)
 	defer gt.done()
 
-	// commit more work on master
+	// commit more work on main
 	write(t, gt.server+"/file", "more work", 0644)
 	trun(t, gt.server, "git", "commit", "-m", "work", "file")
 
 	// update client
-	trun(t, gt.client, "git", "checkout", "master")
+	trun(t, gt.client, "git", "checkout", "main")
 	trun(t, gt.client, "git", "pull")
 
 	hash := strings.TrimSpace(trun(t, gt.client, "git", "rev-parse", "HEAD"))
@@ -178,7 +178,7 @@ func TestBranchpointMerge(t *testing.T) {
 	if bp != hash {
 		t.Logf("branches:\n%s", trun(t, gt.client, "git", "branch", "-a", "-v"))
 		t.Logf("log:\n%s", trun(t, gt.client, "git", "log", "--graph", "--decorate"))
-		t.Logf("log origin/master..HEAD:\n%s", trun(t, gt.client, "git", "log", "origin/master..HEAD"))
+		t.Logf("log origin/main..HEAD:\n%s", trun(t, gt.client, "git", "log", "origin/main..HEAD"))
 		t.Fatalf("branchpoint=%q, want %q", bp, hash)
 	}
 }
diff --git a/git-codereview/change_test.go b/git-codereview/change_test.go
index e9337dc..206ed82 100644
--- a/git-codereview/change_test.go
+++ b/git-codereview/change_test.go
@@ -14,28 +14,28 @@ func TestChange(t *testing.T) {
 	gt := newGitTest(t)
 	defer gt.done()
 
-	t.Logf("master -> master")
-	testMain(t, "change", "master")
-	testRan(t, "git checkout -q master")
+	t.Logf("main -> main")
+	testMain(t, "change", "main")
+	testRan(t, "git checkout -q main")
 
 	testCommitMsg = "foo: my commit msg"
-	t.Logf("master -> work")
+	t.Logf("main -> work")
 	testMain(t, "change", "work")
 	testRan(t, "git checkout -q -b work",
-		"git branch -q --set-upstream-to origin/master")
+		"git branch -q --set-upstream-to origin/main")
 
-	t.Logf("work -> master")
-	testMain(t, "change", "master")
-	testRan(t, "git checkout -q master")
+	t.Logf("work -> main")
+	testMain(t, "change", "main")
+	testRan(t, "git checkout -q main")
 
-	t.Logf("master -> work with staged changes")
+	t.Logf("main -> work with staged changes")
 	write(t, gt.client+"/file", "new content", 0644)
 	trun(t, gt.client, "git", "add", "file")
 	testMain(t, "change", "work")
 	testRan(t, "git checkout -q work",
 		"git commit -q --allow-empty -m foo: my commit msg")
 
-	t.Logf("master -> dev.branch")
+	t.Logf("main -> dev.branch")
 	testMain(t, "change", "dev.branch")
 	testRan(t, "git checkout -q -t -b dev.branch origin/dev.branch")
 }
@@ -52,13 +52,13 @@ func TestChangeAhead(t *testing.T) {
 	gt := newGitTest(t)
 	defer gt.done()
 
-	// commit to master (mistake)
+	// commit to main (mistake)
 	write(t, gt.client+"/file", "new content", 0644)
 	trun(t, gt.client, "git", "add", "file")
 	trun(t, gt.client, "git", "commit", "-m", "msg")
 
 	testMainDied(t, "change", "work")
-	testPrintedStderr(t, "bad repo state: branch master is ahead of origin/master")
+	testPrintedStderr(t, "bad repo state: branch main is ahead of origin/main")
 }
 
 func TestMessageRE(t *testing.T) {
@@ -117,7 +117,7 @@ func TestChangeCL(t *testing.T) {
 	// Ensure that 'change' with a CL accepts we have gerrit. Test address is injected by newGerritServer.
 	write(t, gt.server+"/codereview.cfg", "gerrit: on", 0644)
 	trun(t, gt.server, "git", "add", "codereview.cfg")
-	trun(t, gt.server, "git", "commit", "-m", "codereview.cfg on master")
+	trun(t, gt.server, "git", "commit", "-m", "codereview.cfg on main")
 	trun(t, gt.client, "git", "pull")
 	defer srv.done()
 
@@ -140,7 +140,7 @@ func TestChangeCL(t *testing.T) {
 	}})
 
 	checkChangeCL := func(arg, ref, hash string) {
-		testMain(t, "change", "master")
+		testMain(t, "change", "main")
 		testMain(t, "change", arg)
 		testRan(t,
 			fmt.Sprintf("git fetch -q origin %s", ref),
diff --git a/git-codereview/gofmt_test.go b/git-codereview/gofmt_test.go
index 0bd6aa9..81f82a4 100644
--- a/git-codereview/gofmt_test.go
+++ b/git-codereview/gofmt_test.go
@@ -255,33 +255,33 @@ func TestGofmtFastForwardMerge(t *testing.T) {
 	gt := newGitTest(t)
 	defer gt.done()
 
-	// merge dev.branch into master
+	// merge dev.branch into main
 	write(t, gt.server+"/file", "more work", 0644)
 	trun(t, gt.server, "git", "commit", "-m", "work", "file")
 	trun(t, gt.server, "git", "merge", "-m", "merge", "dev.branch")
 
-	// add bad go file on master
+	// add bad go file on main
 	write(t, gt.server+"/bad.go", "package {\n", 0644)
 	trun(t, gt.server, "git", "add", "bad.go")
 	trun(t, gt.server, "git", "commit", "-m", "bad go")
 
 	// update client
-	trun(t, gt.client, "git", "checkout", "master")
+	trun(t, gt.client, "git", "checkout", "main")
 	trun(t, gt.client, "git", "pull")
 	testMain(t, "change", "dev.branch")
 	trun(t, gt.client, "git", "pull")
 
-	// merge master into dev.branch, fast forward merge
-	trun(t, gt.client, "git", "merge", "--ff-only", "master")
+	// merge main into dev.branch, fast forward merge
+	trun(t, gt.client, "git", "merge", "--ff-only", "main")
 
 	// verify that now client is in a state where just the tag is changing; there's no new commit.
-	masterHash := strings.TrimSpace(trun(t, gt.server, "git", "rev-parse", "master"))
+	mainHash := strings.TrimSpace(trun(t, gt.server, "git", "rev-parse", "main"))
 	devHash := strings.TrimSpace(trun(t, gt.client, "git", "rev-parse", "HEAD"))
 
-	if masterHash != devHash {
+	if mainHash != devHash {
 		t.Logf("branches:\n%s", trun(t, gt.client, "git", "branch", "-a", "-v"))
 		t.Logf("log:\n%s", trun(t, gt.client, "git", "log", "--graph", "--decorate"))
-		t.Fatalf("setup wrong - got different commit hashes on master and dev branch")
+		t.Fatalf("setup wrong - got different commit hashes on main and dev branch")
 	}
 
 	// check that gofmt finds nothing to do, ignoring the bad (but committed) file1.go.
diff --git a/git-codereview/hook_test.go b/git-codereview/hook_test.go
index e9dc1c3..d4ffbc4 100644
--- a/git-codereview/hook_test.go
+++ b/git-codereview/hook_test.go
@@ -210,10 +210,10 @@ func testHookCommitMsgBranchPrefix(t *testing.T, gerrit bool) {
 	}
 
 	// Master has no prefix.
-	testMain(t, "change", "master")
+	testMain(t, "change", "main")
 	checkPrefix("Test message.\n")
 
-	// Work branch from master has no prefix.
+	// Work branch from main has no prefix.
 	testMain(t, "change", "work")
 	checkPrefix("Test message.\n")
 }
diff --git a/git-codereview/mail_test.go b/git-codereview/mail_test.go
index c655b54..b754d3b 100644
--- a/git-codereview/mail_test.go
+++ b/git-codereview/mail_test.go
@@ -26,7 +26,7 @@ func TestMail(t *testing.T) {
 
 	testMain(t, "mail")
 	testRan(t,
-		"git push -q origin HEAD:refs/for/master",
+		"git push -q origin HEAD:refs/for/main",
 		"git tag -f work.mailed "+h)
 }
 
@@ -153,14 +153,14 @@ func TestMailMultiple(t *testing.T) {
 	h := CurrentBranch().Pending()[1].ShortHash
 	testMain(t, "mail", "HEAD^")
 	testRan(t,
-		"git push -q origin "+h+":refs/for/master",
+		"git push -q origin "+h+":refs/for/main",
 		"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 push -q origin HEAD:refs/for/main",
 		"git tag -f work.mailed "+h)
 }
 
@@ -203,17 +203,17 @@ func TestMailShort(t *testing.T) {
 
 	testMain(t, "mail")
 	testRan(t,
-		"git push -q origin HEAD:refs/for/master",
+		"git push -q origin HEAD:refs/for/main",
 		"git tag -f work.mailed "+h)
 
 	testMain(t, "mail", "-r", "r1")
 	testRan(t,
-		"git push -q origin HEAD:refs/for/master%r=r1@golang.org",
+		"git push -q origin HEAD:refs/for/main%r=r1@golang.org",
 		"git tag -f work.mailed "+h)
 
 	testMain(t, "mail", "-r", "other,anon", "-cc", "r1,full@email.com")
 	testRan(t,
-		"git push -q origin HEAD:refs/for/master%r=other@golang.org,r=anon@golang.org,cc=r1@golang.org,cc=full@email.com",
+		"git push -q origin HEAD:refs/for/main%r=other@golang.org,r=anon@golang.org,cc=r1@golang.org,cc=full@email.com",
 		"git tag -f work.mailed "+h)
 
 	testMainDied(t, "mail", "-r", "other", "-r", "anon,r1,missing")
@@ -229,7 +229,7 @@ func TestWIP(t *testing.T) {
 
 	testMain(t, "mail", "-wip")
 	testRan(t,
-		"git push -q origin HEAD:refs/for/master%wip",
+		"git push -q origin HEAD:refs/for/main%wip",
 		"git tag -f work.mailed "+h)
 }
 
@@ -253,7 +253,7 @@ func TestMailTopic(t *testing.T) {
 
 	testMain(t, "mail", "-topic", "test-topic")
 	testRan(t,
-		"git push -q origin HEAD:refs/for/master%topic=test-topic",
+		"git push -q origin HEAD:refs/for/main%topic=test-topic",
 		"git tag -f work.mailed "+h)
 }
 
@@ -274,11 +274,11 @@ func TestMailHashtag(t *testing.T) {
 
 	testMain(t, "mail", "-hashtag", "test1,test2")
 	testRan(t,
-		"git push -q origin HEAD:refs/for/master%hashtag=test1,hashtag=test2",
+		"git push -q origin HEAD:refs/for/main%hashtag=test1,hashtag=test2",
 		"git tag -f work.mailed "+h)
 	testMain(t, "mail", "-hashtag", "")
 	testRan(t,
-		"git push -q origin HEAD:refs/for/master",
+		"git push -q origin HEAD:refs/for/main",
 		"git tag -f work.mailed "+h)
 
 	testMainDied(t, "mail", "-hashtag", "test1,,test3")
@@ -299,7 +299,7 @@ func TestMailEmpty(t *testing.T) {
 
 	testMain(t, "change", "work")
 	testRan(t, "git checkout -q -b work",
-		"git branch -q --set-upstream-to origin/master")
+		"git branch -q --set-upstream-to origin/main")
 
 	t.Logf("creating empty change")
 	testCommitMsg = "foo: this commit will be empty"
diff --git a/git-codereview/pending.go b/git-codereview/pending.go
index bd8d508..e17a905 100644
--- a/git-codereview/pending.go
+++ b/git-codereview/pending.go
@@ -247,7 +247,7 @@ func cmdPending(args []string) {
 		if n := b.CommitsBehind(); n > 0 {
 			tags = append(tags, fmt.Sprintf("%d behind", n))
 		}
-		if b.OriginBranch() != "origin/master" {
+		if br := b.OriginBranch(); br != "origin/master" && br != "origin/main" {
 			tags = append(tags, "tracking "+strings.TrimPrefix(b.OriginBranch(), "origin/"))
 		}
 		if len(tags) > 0 {
diff --git a/git-codereview/pending_test.go b/git-codereview/pending_test.go
index ee5e947..ccb2f76 100644
--- a/git-codereview/pending_test.go
+++ b/git-codereview/pending_test.go
@@ -22,7 +22,7 @@ func TestPendingNone(t *testing.T) {
 	defer gt.done()
 
 	testPending(t, `
-		master (current branch)
+		main (current branch)
 
 	`)
 }
@@ -69,13 +69,13 @@ func TestPendingComplex(t *testing.T) {
 	trun(t, gt.server, "git", "commit", "-a", "-m", "v3")
 
 	trun(t, gt.client, "git", "fetch")
-	trun(t, gt.client, "git", "checkout", "-b", "work3ignored", "-t", "origin/master")
+	trun(t, gt.client, "git", "checkout", "-b", "work3ignored", "-t", "origin/main")
 
 	write(t, gt.server+"/file", "v4", 0644)
 	trun(t, gt.server, "git", "commit", "-a", "-m", "v4")
 
 	trun(t, gt.client, "git", "fetch")
-	trun(t, gt.client, "git", "checkout", "-b", "work2", "-t", "origin/master")
+	trun(t, gt.client, "git", "checkout", "-b", "work2", "-t", "origin/main")
 	write(t, gt.client+"/file", "modify", 0644)
 	write(t, gt.client+"/file1", "new", 0644)
 	trun(t, gt.client, "git", "add", "file", "file1")
@@ -159,14 +159,14 @@ func TestPendingErrors(t *testing.T) {
 	gt.enableGerrit(t)
 	defer gt.done()
 
-	trun(t, gt.client, "git", "checkout", "master")
+	trun(t, gt.client, "git", "checkout", "main")
 	write(t, gt.client+"/file", "v3", 0644)
 	trun(t, gt.client, "git", "commit", "-a", "-m", "v3")
 
 	testPending(t, `
-		master REVHASH..REVHASH (current branch)
-			ERROR: Branch contains 1 commit not on origin/master.
-				Do not commit directly to master branch.
+		main REVHASH..REVHASH (current branch)
+			ERROR: Branch contains 1 commit not on origin/main.
+				Do not commit directly to main branch.
 		
 		+ REVHASH
 			v3
@@ -177,9 +177,9 @@ func TestPendingErrors(t *testing.T) {
 	`)
 
 	testPendingArgs(t, []string{"-s"}, `
-		master REVHASH..REVHASH (current branch)
-			ERROR: Branch contains 1 commit not on origin/master.
-				Do not commit directly to master branch.
+		main REVHASH..REVHASH (current branch)
+			ERROR: Branch contains 1 commit not on origin/main.
+				Do not commit directly to main branch.
 		+ REVHASH v3
 
 	`)
@@ -446,7 +446,7 @@ func TestPendingGerritMultiChange15(t *testing.T) {
 
 func testPendingReply(srv *gerritServer, id, rev, status string) {
 	srv.setJSON(id, `{
-		"id": "proj~master~`+id+`",
+		"id": "proj~main~`+id+`",
 		"project": "proj",
 		"current_revision": "`+rev+`",
 		"status": "`+status+`",
diff --git a/git-codereview/submit_test.go b/git-codereview/submit_test.go
index 3f893ec..fbe2cb3 100644
--- a/git-codereview/submit_test.go
+++ b/git-codereview/submit_test.go
@@ -94,9 +94,9 @@ func TestSubmitErrors(t *testing.T) {
 	t.Logf("> submit with unexpected status")
 	const newJSON = `{"status": "NEW", "labels": {"Code-Review": {"approved": {}}}}`
 	srv.setJSON(id, newJSON)
-	srv.setReply("/a/changes/proj~master~I123456789/submit", gerritReply{body: ")]}'\n" + newJSON})
+	srv.setReply("/a/changes/proj~main~I123456789/submit", gerritReply{body: ")]}'\n" + newJSON})
 	testMainDied(t, "submit")
-	testRan(t, "git push -q origin HEAD:refs/for/master")
+	testRan(t, "git push -q origin HEAD:refs/for/main")
 	testPrintedStderr(t, "submit error: unexpected post-submit Gerrit change status \"NEW\"")
 }
 
@@ -109,15 +109,15 @@ func TestSubmitTimeout(t *testing.T) {
 	gt.work(t)
 
 	setJSON := func(json string) {
-		srv.setReply("/a/changes/proj~master~I123456789", gerritReply{body: ")]}'\n" + json})
+		srv.setReply("/a/changes/proj~main~I123456789", gerritReply{body: ")]}'\n" + json})
 	}
 
 	t.Log("> submit with timeout")
 	const submittedJSON = `{"status": "SUBMITTED", "mergeable": true, "labels": {"Code-Review": {"approved": {}}}}`
 	setJSON(submittedJSON)
-	srv.setReply("/a/changes/proj~master~I123456789/submit", gerritReply{body: ")]}'\n" + submittedJSON})
+	srv.setReply("/a/changes/proj~main~I123456789/submit", gerritReply{body: ")]}'\n" + submittedJSON})
 	testMainDied(t, "submit")
-	testRan(t, "git push -q origin HEAD:refs/for/master")
+	testRan(t, "git push -q origin HEAD:refs/for/main")
 	testPrintedStderr(t, "cannot submit: timed out waiting for change to be submitted by Gerrit")
 }
 
@@ -144,7 +144,7 @@ func TestSubmit(t *testing.T) {
 	)
 	submitted := false
 	npoll := 0
-	srv.setReply("/a/changes/proj~master~I123456789", gerritReply{f: func() gerritReply {
+	srv.setReply("/a/changes/proj~main~I123456789", gerritReply{f: func() gerritReply {
 		if !submitted {
 			return gerritReply{body: ")]}'\n" + newJSON}
 		}
@@ -153,7 +153,7 @@ func TestSubmit(t *testing.T) {
 		}
 		return gerritReply{body: ")]}'\n" + mergedJSON}
 	}})
-	srv.setReply("/a/changes/proj~master~I123456789/submit", gerritReply{f: func() gerritReply {
+	srv.setReply("/a/changes/proj~main~I123456789/submit", gerritReply{f: func() gerritReply {
 		if submitted {
 			return gerritReply{status: 409}
 		}
@@ -235,20 +235,20 @@ func testSubmitMultiple(t *testing.T, gt *gitTest, srv *gerritServer) (*GerritCh
 		Labels:          map[string]*GerritLabel{"Code-Review": &GerritLabel{Approved: new(GerritAccount)}},
 	}
 
-	srv.setReply("/a/changes/proj~master~I0000001", gerritReply{f: func() gerritReply {
+	srv.setReply("/a/changes/proj~main~I0000001", gerritReply{f: func() gerritReply {
 		return gerritReply{json: cl1}
 	}})
-	srv.setReply("/a/changes/proj~master~I0000001/submit", gerritReply{f: func() gerritReply {
+	srv.setReply("/a/changes/proj~main~I0000001/submit", gerritReply{f: func() gerritReply {
 		if cl1.Status != "NEW" {
 			return gerritReply{status: 409}
 		}
 		cl1.Status = "MERGED"
 		return gerritReply{json: cl1}
 	}})
-	srv.setReply("/a/changes/proj~master~I0000002", gerritReply{f: func() gerritReply {
+	srv.setReply("/a/changes/proj~main~I0000002", gerritReply{f: func() gerritReply {
 		return gerritReply{json: cl2}
 	}})
-	srv.setReply("/a/changes/proj~master~I0000002/submit", gerritReply{f: func() gerritReply {
+	srv.setReply("/a/changes/proj~main~I0000002/submit", gerritReply{f: func() gerritReply {
 		if cl2.Status != "NEW" {
 			return gerritReply{status: 409}
 		}
diff --git a/git-codereview/util_test.go b/git-codereview/util_test.go
index 8acdb66..90a5b93 100644
--- a/git-codereview/util_test.go
+++ b/git-codereview/util_test.go
@@ -83,7 +83,7 @@ func (gt *gitTest) work(t *testing.T) {
 	t.Helper()
 	if gt.nwork == 0 {
 		trun(t, gt.client, "git", "checkout", "-b", "work")
-		trun(t, gt.client, "git", "branch", "--set-upstream-to", "origin/master")
+		trun(t, gt.client, "git", "branch", "--set-upstream-to", "origin/main")
 		trun(t, gt.client, "git", "tag", "work") // make sure commands do the right thing when there is a tag of the same name
 	}
 
@@ -142,22 +142,35 @@ func newGitTest(t *testing.T) (gt *gitTest) {
 	server := tmpdir + "/git-origin"
 
 	mkdir(t, server)
-	write(t, server+"/file", "this is master", 0644)
+	write(t, server+"/file", "this is main", 0644)
 	write(t, server+"/.gitattributes", "* -text\n", 0644)
 	trun(t, server, "git", "init", ".")
 	trun(t, server, "git", "config", "user.name", "gopher")
 	trun(t, server, "git", "config", "user.email", "gopher@example.com")
 	trun(t, server, "git", "add", "file", ".gitattributes")
-	trun(t, server, "git", "commit", "-m", "on master")
+	trun(t, server, "git", "commit", "-m", "initial commit")
+
+	// Newer gits use a default branch name of main.
+	// Older ones used master.
+	// So the branch name now may be main or master.
+	// We would like to assume main for the tests.
+	// Newer gits would let us do
+	//	git init --initial-branch=main .
+	// above, but older gits don't have initial-branch.
+	// And we don't trust older gits to handle a no-op branch rename.
+	// So rename it to something different, and then to main.
+	// Then we'll be in a known state.
+	trun(t, server, "git", "branch", "-M", "certainly-not-main")
+	trun(t, server, "git", "branch", "-M", "main")
 
 	for _, name := range []string{"dev.branch", "release.branch"} {
-		trun(t, server, "git", "checkout", "master")
+		trun(t, server, "git", "checkout", "main")
 		trun(t, server, "git", "checkout", "-b", name)
 		write(t, server+"/file."+name, "this is "+name, 0644)
 		trun(t, server, "git", "add", "file."+name)
 		trun(t, server, "git", "commit", "-m", "on "+name)
 	}
-	trun(t, server, "git", "checkout", "master")
+	trun(t, server, "git", "checkout", "main")
 
 	client := tmpdir + "/git-client"
 	mkdir(t, client)
@@ -439,7 +452,7 @@ func (s *gerritServer) setReply(path string, reply gerritReply) {
 }
 
 func (s *gerritServer) setJSON(id, json string) {
-	s.setReply("/a/changes/proj~master~"+id, gerritReply{body: ")]}'\n" + json})
+	s.setReply("/a/changes/proj~main~"+id, gerritReply{body: ")]}'\n" + json})
 }
 
 func (s *gerritServer) ServeHTTP(w http.ResponseWriter, req *http.Request) {