2 files changed, 48 insertions, 4 deletions
diff --git a/pkg/git/git.go b/pkg/git/git.go
index a239453f8..e3dc8a142 100644
--- a/pkg/git/git.go
+++ b/pkg/git/git.go
@@ -81,16 +81,37 @@ func HeadCommit(dir string) (string, error) {
 	return string(output), nil
 }
 
-// ListRecentCommits returns list of commit titles for the last year starting from baseCommit.
+// ListRecentCommits returns list of recent commit titles starting from baseCommit.
 func ListRecentCommits(dir, baseCommit string) ([]string, error) {
-	since := time.Now().Add(-time.Hour * 24 * 365).Format("01-02-2006")
-	// On upstream kernel this produces 3.5MB of output.
+	// On upstream kernel this produces ~11MB of output.
 	// Somewhat inefficient to collect whole output in a slice
 	// and then convert to string, but should be bearable.
 	output, err := osutil.RunCmd(timeout, dir, "git", "log",
-		"--pretty=format:%s", "--no-merges", "--since", since, baseCommit)
+		"--pretty=format:%s", "--no-merges", "-n", "200000", baseCommit)
 	if err != nil {
 		return nil, err
 	}
 	return strings.Split(string(output), "\n"), nil
 }
+
+// CanonicalizeCommit returns commit title that can be used when checking
+// if a particular commit is present in a git tree.
+// Some trees add prefixes to commit titles during backporting,
+// so we want e.g. commit "foo bar" match "BACKPORT: foo bar".
+func CanonicalizeCommit(title string) string {
+	for _, prefix := range commitPrefixes {
+		if strings.HasPrefix(title, prefix) {
+			title = title[len(prefix):]
+			break
+		}
+	}
+	return strings.TrimSpace(title)
+}
+
+var commitPrefixes = []string{
+	"UPSTREAM:",
+	"CHROMIUM:",
+	"FROMLIST:",
+	"BACKPORT:",
+	"net-backports:",
+}
diff --git a/pkg/git/git_test.go b/pkg/git/git_test.go
new file mode 100644
index 000000000..42d2d3a07
--- /dev/null
+++ b/pkg/git/git_test.go
@@ -0,0 +1,23 @@
+// Copyright 2017 syzkaller project authors. All rights reserved.
+// Use of this source code is governed by Apache 2 LICENSE that can be found in the LICENSE file.
+
+package git
+
+import (
+	"testing"
+)
+
+func TestCanonicalizeCommit(t *testing.T) {
+	tests := map[string]string{
+		"foo bar":                     "foo bar",
+		" foo ":                       "foo",
+		"UPSTREAM: foo bar":           "foo bar",
+		"BACKPORT: UPSTREAM: foo bar": "UPSTREAM: foo bar",
+	}
+	for in, want := range tests {
+		got := CanonicalizeCommit(in)
+		if got != want {
+			t.Errorf("input %q: got %q, want %q", in, got, want)
+		}
+	}
+}