lib/ignores: Fix ignore loading, report errors to UI (fixes #4901) (#4932)

lib/ignore/ignore.go

@@ -140,9 +140,14 @@ func (m *Matcher) Load(file string) error {
 	defer fd.Close()
 
 	m.changeDetector.Reset()
-	m.changeDetector.Remember(m.fs, file, info.ModTime())
 
-	return m.parseLocked(fd, file)
+	err = m.parseLocked(fd, file)
+	// If we failed to parse, don't cache, as next time Load is called
+	// we'll pretend it's all good.
+	if err == nil {
+		m.changeDetector.Remember(m.fs, file, info.ModTime())
+	}
+	return err
 }
 
 func (m *Matcher) Parse(r io.Reader, file string) error {
@@ -445,6 +450,12 @@ func parseIgnoreFile(fs fs.Filesystem, fd io.Reader, currentFile string, cd Chan
 			var includePatterns []Pattern
 			if includePatterns, err = loadParseIncludeFile(fs, includeFile, cd, linesSeen); err == nil {
 				patterns = append(patterns, includePatterns...)
+			} else {
+				// Wrap the error, as if the include does not exist, we get a
+				// IsNotExists(err) == true error, which we use to check
+				// existance of the .stignore file, and just end up assuming
+				// there is none, rather than a broken include.
+				err = fmt.Errorf("failed to load include file %s: %s", includeFile, err.Error())
 			}
 		case strings.HasSuffix(line, "/**"):
 			err = addPattern(line)

lib/ignore/ignore_test.go

@@ -981,3 +981,42 @@ func TestIssue4689(t *testing.T) {
 		t.Fatalf("wrong lines parsing changed comment:\n%v", lines)
 	}
 }
+
+func TestIssue4901(t *testing.T) {
+	dir, err := ioutil.TempDir("", "")
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	defer os.RemoveAll(dir)
+
+	stignore := `
+	#include unicorn-lazor-death
+	puppy
+	`
+
+	if err := ioutil.WriteFile(filepath.Join(dir, ".stignore"), []byte(stignore), 0777); err != nil {
+		t.Fatalf(err.Error())
+	}
+
+	pats := New(fs.NewFilesystem(fs.FilesystemTypeBasic, dir), WithCache(true))
+	// Cache does not suddenly make the load succeed.
+	for i := 0; i < 2; i++ {
+		err := pats.Load(".stignore")
+		if err == nil {
+			t.Fatalf("expected an error")
+		}
+		if fs.IsNotExist(err) {
+			t.Fatalf("unexpected error type")
+		}
+	}
+
+	if err := ioutil.WriteFile(filepath.Join(dir, "unicorn-lazor-death"), []byte(" "), 0777); err != nil {
+		t.Fatalf(err.Error())
+	}
+
+	err = pats.Load(".stignore")
+	if err != nil {
+		t.Fatalf("unexpected error: %s", err.Error())
+	}
+}

lib/model/model.go

@@ -1490,11 +1490,10 @@ func (m *Model) GetIgnores(folder string) ([]string, []string, error) {
 	}
 
 	ignores, ok := m.folderIgnores[folder]
-	if ok {
+	if !ok {
-		return ignores.Lines(), ignores.Patterns(), nil
+		ignores = ignore.New(fs.NewFilesystem(cfg.FilesystemType, cfg.Path))
 	}
 
-	ignores = ignore.New(fs.NewFilesystem(cfg.FilesystemType, cfg.Path))
 	if err := ignores.Load(".stignore"); err != nil && !fs.IsNotExist(err) {
 		return nil, nil, err
 	}