Bugfix: Overlay accessor failed to wrap LStat output (#4685)

Fixes: #4610

Author: scudette

accessors/api.go

@@ -226,6 +226,21 @@ func (self *OSPath) TrimComponents(components ...string) *OSPath {
 	return result
 }
 
+// Does the path has the required prefix?
+func (self *OSPath) HasPrefix(components ...string) bool {
+	if len(self.Components) > len(components) {
+		return false
+	}
+
+	for idx, c := range components {
+		if !self.Manipulator.ComponentEqual(c, self.Components[idx]) {
+			return false
+		}
+	}
+
+	return true
+}
+
 // Produce a human readable string - this is a one way conversion: It
 // is not possible to go back to a proper OSPath from this.
 func (self *OSPath) HumanString(scope types.Scope) string {

accessors/overlay/fixtures/TestOverlay.golden

@@ -1,5 +1,8 @@
 {
- "/file1.txt": "Hello",
- "/file2.txt": "Hello Two",
- "/subdir/file2.txt": "Hello Subdir"
+ "file1.txt": "Hello",
+ "file1.txt Stat": "file1.txt",
+ "file2.txt": "Hello Two",
+ "file2.txt Stat": "file2.txt",
+ "subdir:file2.txt": "Hello Subdir",
+ "subdir:file2.txt Stat": "subdir:file2.txt"
 }

accessors/overlay/overlay.go

@@ -16,7 +16,7 @@ import (
 )
 
 type OverlayFileSystemAccessorArgs struct {
-	Paths    []*accessors.OSPath `vfilter:"required,field=paths,doc=A list of paths to try to resolve each path."`
+	Paths    []*accessors.OSPath `vfilter:"required,field=paths,doc=A list of paths to try to resolve."`
 	Accessor string              `vfilter:"optional,field=accessor,doc=File accessor"`
 }
 
@@ -74,17 +74,19 @@ func (self OverlayFileSystemAccessor) ReadDirWithOSPath(
 		return nil, err
 	}
 
-	base, _ := accessors.NewGenericOSPath("/")
-
 	for _, basepath := range overlayer.Paths {
 		delegate_path := basepath.Append(path.Components...)
 		delegate_dir, err := accessor.ReadDirWithOSPath(delegate_path)
 		if err != nil {
 			continue
 		}
+
+		base := basepath.TrimComponents(basepath.Components...)
+
 		for _, fsinfo := range delegate_dir {
-			res = append(res, accessors.NewFileInfoWrapper(
-				fsinfo, base, basepath.Copy()))
+			item := accessors.NewFileInfoWrapper(
+				fsinfo, base, basepath.Copy())
+			res = append(res, item)
 		}
 	}
 
@@ -158,6 +160,8 @@ func (self OverlayFileSystemAccessor) LstatWithOSPath(
 			basepath.Append(path.Components...))
 		// Return the first successful opened file
 		if res_err == nil {
+			base := basepath.TrimComponents(basepath.Components...)
+			res = accessors.NewFileInfoWrapper(res, base, basepath.Copy())
 			break
 		}
 	}

accessors/overlay/overlay_test.go

@@ -90,7 +90,15 @@ func (self *OverlayAccessorTestSuite) TestOverlay() {
 			assert.NoError(self.T(), err)
 			fd.Close()
 
-			golden.Set(f.OSPath().String(), string(data))
+			components := strings.Join(f.OSPath().Components, ":")
+
+			golden.Set(components, string(data))
+
+			stat, err := accessor.LstatWithOSPath(f.OSPath())
+			assert.NoError(self.T(), err)
+
+			golden.Set(components+" Stat",
+				strings.Join(stat.OSPath().Components, ":"))
 		}
 	}
 	check_dir("/")