git-codereview: disable message about skipped cherry-picks in sync

Sync very frequently is done to zero out submitted CLs.
New git versions print

	hint: use --reapply-cherry-picks to include skipped commits
	hint: Disable this message with "git config advice.skippedCherryPicks false"

This message is noise more often than signal, so disable it during sync.

Change-Id: Ida8867cbd614027f43bbbe6e6389a8920aae5293
Reviewed-on: https://go-review.googlesource.com/c/review/+/351209
Trust: Russ Cox <rsc@golang.org>
Run-TryBot: Russ Cox <rsc@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gopher Robot <gobot@golang.org>
diff --git a/git-codereview/sync.go b/git-codereview/sync.go
index 2d93bcb..f8233f1 100644
--- a/git-codereview/sync.go
+++ b/git-codereview/sync.go
@@ -56,10 +56,16 @@
 	// We want to pull in the remote changes from the upstream branch
 	// and rebase the current pending commit (if any) on top of them.
 	// If there is no pending commit, the pull will do a fast-forward merge.
+	//
+	// The -c advice.skippedCherryPicks=false disables this message:
+	//
+	//	hint: use --reapply-cherry-picks to include skipped commits
+	//	hint: Disable this message with "git config advice.skippedCherryPicks false"
+	//
 	if *verbose > 1 {
-		run("git", "pull", "-q", "-r", "-v", "origin", strings.TrimPrefix(b.OriginBranch(), "origin/"))
+		run("git", "-c", "advice.skippedCherryPicks=false", "pull", "-q", "-r", "-v", "origin", strings.TrimPrefix(b.OriginBranch(), "origin/"))
 	} else {
-		run("git", "pull", "-q", "-r", "origin", strings.TrimPrefix(b.OriginBranch(), "origin/"))
+		run("git", "-c", "advice.skippedCherryPicks=false", "pull", "-q", "-r", "origin", strings.TrimPrefix(b.OriginBranch(), "origin/"))
 	}
 
 	b = CurrentBranch() // discard any cached information
diff --git a/git-codereview/sync_test.go b/git-codereview/sync_test.go
index 31f4800..884168c 100644
--- a/git-codereview/sync_test.go
+++ b/git-codereview/sync_test.go
@@ -118,15 +118,15 @@
 	// also exercising -v parsing.
 	testMain(t, "sync", "-v=true")
 	testNoStdout(t)
-	testPrintedStderr(t, "git pull -q -r origin main")
+	testPrintedStderr(t, "git -c advice.skippedCherryPicks=false pull -q -r origin main")
 
 	testMain(t, "sync", "-v=1")
 	testNoStdout(t)
-	testPrintedStderr(t, "git pull -q -r origin main")
+	testPrintedStderr(t, "git -c advice.skippedCherryPicks=false pull -q -r origin main")
 
 	testMain(t, "sync", "-v")
 	testNoStdout(t)
-	testPrintedStderr(t, "git pull -q -r origin main")
+	testPrintedStderr(t, "git -c advice.skippedCherryPicks=false pull -q -r origin main")
 
 	testMain(t, "sync", "-v=false")
 	testNoStdout(t)