pkg/report: fix Start/EndPos calculation for fuchsia

We computed Start/EndPos after trimming line prefix,
this resulted in offsetted values which are not correct.
Fix that. Add more tests and checks for Start/EndPos.

3 files changed, 46 insertions, 5 deletions

diff --git a/pkg/report/fuchsia.go b/pkg/report/fuchsia.go
index 5e80501ab..cafef6bd2 100644
--- a/pkg/report/fuchsia.go
+++ b/pkg/report/fuchsia.go
@@ -74,7 +74,7 @@ func (ctx *fuchsia) Parse(output []byte) *Report {
 func (ctx *fuchsia) shortenReport(report []byte) []byte {
 	out := new(bytes.Buffer)
 	for s := bufio.NewScanner(bytes.NewReader(report)); s.Scan(); {
-		line := s.Bytes()
+		line := zirconLinePrefix.ReplaceAll(s.Bytes(), nil)
 		if matchesAny(line, zirconUnrelated) {
 			continue
 		}
@@ -92,7 +92,7 @@ func (ctx *fuchsia) symbolize(output []byte) []byte {
 	defer symb.Close()
 	out := new(bytes.Buffer)
 	for s := bufio.NewScanner(bytes.NewReader(output)); s.Scan(); {
-		line := zirconLinePrefix.ReplaceAll(s.Bytes(), nil)
+		line := s.Bytes()
 		if bytes.Contains(line, zirconAssertFailed) && len(line) == 127 {
 			// This is super hacky: but zircon splits the most important information in long assert lines
 			// (and they are always long) into several lines in irreversible way. Try to restore full line.
@@ -324,7 +324,7 @@ var zirconOopses = []*oops{
 		[]oopsFormat{
 			{
 				title:        compile("panic: .*"),
-				report:       compile("panic: (.*)(?:.*\\n)+?goroutine"),
+				report:       compile("panic: (.*)(?:.*\\n)+?.* goroutine"),
 				fmt:          "panic: %[1]v",
 				noStackTrace: true,
 			},
diff --git a/pkg/report/report_test.go b/pkg/report/report_test.go
index d5e381dda..9943add00 100644
--- a/pkg/report/report_test.go
+++ b/pkg/report/report_test.go
@@ -168,8 +168,21 @@ func testParseImpl(t *testing.T, reporter Reporter, test *ParseTest) {
 	if title != "" && len(rep.Report) == 0 {
 		t.Fatalf("found crash message but report is empty")
 	}
-	if rep != nil {
-		checkReport(t, rep, test)
+	if rep == nil {
+		return
+	}
+	checkReport(t, rep, test)
+	if rep.StartPos != 0 {
+		// If we parse from StartPos, we must find the same report.
+		rep1 := reporter.Parse(test.Log[rep.StartPos:])
+		if rep1 == nil || rep1.Title != rep.Title {
+			t.Fatalf("did not find the same report from rep.StartPos=%v", rep.StartPos)
+		}
+		// If we parse from EndPos, we must not find the same report.
+		rep2 := reporter.Parse(test.Log[rep.EndPos:])
+		if rep2 != nil && rep2.Title == rep.Title {
+			t.Fatalf("found the same report after rep.EndPos=%v", rep.EndPos)
+		}
 	}
 }
 
@@ -180,6 +193,12 @@ func checkReport(t *testing.T, rep *Report, test *ParseTest) {
 	if !bytes.Equal(rep.Output, test.Log) {
 		t.Fatalf("bad Output:\n%s", rep.Output)
 	}
+	if rep.StartPos != 0 && rep.EndPos != 0 && rep.StartPos >= rep.EndPos {
+		t.Fatalf("StartPos=%v >= EndPos=%v", rep.StartPos, rep.EndPos)
+	}
+	if rep.EndPos > len(rep.Output) {
+		t.Fatalf("EndPos=%v > len(Output)=%v", rep.EndPos, len(rep.Output))
+	}
 	if test.StartLine != "" {
 		if test.EndLine == "" {
 			test.EndLine = test.StartLine
diff --git a/pkg/report/testdata/fuchsia/report/30 b/pkg/report/testdata/fuchsia/report/30
new file mode 100644
index 000000000..c44516351
--- /dev/null
+++ b/pkg/report/testdata/fuchsia/report/30
@@ -0,0 +1,22 @@
+TITLE: unexpected kernel reboot
+START: [00000.000] 00000.00000> welcome to Zircon
+
+000> PMM: boot reserve marking WIRED [0x100000, 0x2b5fff]
+[00000.000] 00000.00000> PMM: boot reserve marking WIRED [0x743000, 0xc4ffff]
+[00000.000] 00000.00000> 
+[00000.000] 00000.00000> welcome to Zircon
+[00000.000] 00000.00000> 
+[00000.000] 00000.00000> KASLR: .text section at 0xffffffff00100000
+[00000.000] 00000.00000> INIT: cpu 0, calling hook 0xffffffff001a12b8 (global_prng_seed) at level 0x30000, flags 0x1
+[00000.000] 00000.00000> initializing vm pre-heap
+[00000.000] 00000.00000> VM: marking boot alloc used range [0xc50000, 0xc50040)
+[00000.000] 00000.00000> INIT: cpu 0, calling hook 0xffffffff00142b08 (elf_build_id) at level 0x4fffe, flags 0x1
+[00000.000] 00000.00000> INIT: cpu 0, calling hook 0xffffffff00142c94 (version) at level 0x4ffff, flags 0x1
+[00000.000] 00000.00000> version:
+[00000.000] 00000.00000> 	arch:     x86
+[00000.000] 00000.00000> 	platform: pc
+[00000.000] 00000.00000> 	target:   pc
+[00000.000] 00000.00000> 	project:  x64
+[00000.000] 00000.00000> 	buildid:  git-09a563b00c52cd79375e7ae0d212857ce1647c91
+[00000.000] 00000.00000> 	ELF build ID: a3466affc9bd84b3edf7d5bf0ee25bbfb043a5dd
+[00000.000] 00000.00000> initializing heap