git-codereview: new sync-branch and related fixes

This CL adds a new command, "git codereview sync-branch",
which does the appropriate git merge for the current branch.

This CL also fixes a bug in "git codereview branchpoint",
and therefore also commands like "git codereview pending",
which was getting the branchpoint wrong for merges,
with the effect that a merge showed too many pending CLs.

This CL also fixes a bug in "git codereview change", which was
formerly willing to run "git checkout" with a pending merge,
which had the effect of flattening the merge mysteriously.
Now it detects the merge and refuses to run.

All of this should make merges easier and less error-prone
as we use dev branches more often.

With the earlier CL in this stack that allows working directly
on local branches, this is now a great way to run a merge
updating dev.regabi:

	git change dev.regabi
	git sync-branch

(with appropriate aliases to avoid typing "codereview").

Fixes golang/go#26201.

Change-Id: Ic24603123ca5135a72004309f5bb208ff149c9eb
Reviewed-on: https://go-review.googlesource.com/c/review/+/279772
Trust: Russ Cox <rsc@golang.org>
Run-TryBot: Russ Cox <rsc@golang.org>
TryBot-Result: Go Bot <gobot@golang.org>
Reviewed-by: Matthew Dempsky <mdempsky@google.com>

1 files changed, 19 insertions, 2 deletions

diff --git a/git-codereview/util_test.go b/git-codereview/util_test.go
index b1b5534..a4f0b51 100644
--- a/git-codereview/util_test.go
+++ b/git-codereview/util_test.go
@@ -15,6 +15,8 @@ import (
 	"os/exec"
 	"path/filepath"
 	"reflect"
+	"regexp"
+	"runtime/debug"
 	"strings"
 	"sync"
 	"testing"
@@ -167,7 +169,12 @@ func newGitTest(t *testing.T) (gt *gitTest) {
 		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)
+		cfg := "branch: " + name + "\n"
+		if name == "dev.branch" {
+			cfg += "parent-branch: main\n"
+		}
+		write(t, server+"/codereview.cfg", cfg, 0644)
+		trun(t, server, "git", "add", "file."+name, "codereview.cfg")
 		trun(t, server, "git", "commit", "-m", "on "+name)
 	}
 	trun(t, server, "git", "checkout", "main")
@@ -330,7 +337,7 @@ func testMain(t *testing.T, args ...string) {
 			if died {
 				msg = "died"
 			} else {
-				msg = fmt.Sprintf("panic: %v", err)
+				msg = fmt.Sprintf("panic: %v\n%s", err, debug.Stack())
 			}
 			t.Fatalf("%s\nstdout:\n%sstderr:\n%s", msg, testStdout, testStderr)
 		}
@@ -380,6 +387,16 @@ func testPrinted(t *testing.T, buf *bytes.Buffer, name string, messages ...strin
 	}
 }
 
+func testHideRevHashes(t *testing.T) {
+	for _, b := range []*bytes.Buffer{testStdout, testStderr} {
+		out := b.Bytes()
+		out = regexp.MustCompile(`\b[0-9a-f]{7}\b`).ReplaceAllLiteral(out, []byte("REVHASH"))
+		out = regexp.MustCompile(`\b\d{4}-\d{2}-\d{2}\b`).ReplaceAllLiteral(out, []byte("DATE"))
+		b.Reset()
+		b.Write(out)
+	}
+}
+
 func testPrintedStdout(t *testing.T, messages ...string) {
 	t.Helper()
 	testPrinted(t, testStdout, "stdout", messages...)