Added tests to validate disk name length near MAX_PATH

posix-utils_windows_test.go

@@ -25,6 +25,7 @@ import (
 	"testing"
 )
 
+// Test if various paths work as expected when converted to UNC form
 func TestUNCPaths(t *testing.T) {
 	var testCases = []struct {
 		objName string
@@ -33,18 +34,24 @@ func TestUNCPaths(t *testing.T) {
 		{"/abcdef", true},
 		{"/a/b/c/d/e/f/g", true},
 		{string(bytes.Repeat([]byte("界"), 85)), true},
+		// Each path component must be <= 255 bytes long.
 		{string(bytes.Repeat([]byte("界"), 100)), false},
 		{`\\p\q\r\s\t`, true},
 	}
+	// Instantiate posix object to manage a disk
 	var err error
 	err = os.Mkdir("c:\\testdisk", 0700)
+
+	// Cleanup on exit of test
 	defer os.RemoveAll("c:\\testdisk")
+
 	var fs StorageAPI
 	fs, err = newPosix("c:\\testdisk")
 	if err != nil {
 		t.Fatal(err)
 	}
 
+	// Create volume to use in conjunction with other StorageAPI's file API(s)
 	err = fs.MakeVol("voldir")
 	if err != nil {
 		t.Fatal(err)
@@ -62,9 +69,13 @@ func TestUNCPaths(t *testing.T) {
 	}
 }
 
+// Test to validate posix behaviour on windows when a non-final path component is a file.
 func TestUNCPathENOTDIR(t *testing.T) {
 	var err error
+	// Instantiate posix object to manage a disk
 	err = os.Mkdir("c:\\testdisk", 0700)
+
+	// Cleanup on exit of test
 	defer os.RemoveAll("c:\\testdisk")
 	var fs StorageAPI
 	fs, err = newPosix("c:\\testdisk")
@@ -72,6 +83,7 @@ func TestUNCPathENOTDIR(t *testing.T) {
 		t.Fatal(err)
 	}
 
+	// Create volume to use in conjunction with other StorageAPI's file API(s)
 	err = fs.MakeVol("voldir")
 	if err != nil {
 		t.Fatal(err)
@@ -82,9 +94,68 @@ func TestUNCPathENOTDIR(t *testing.T) {
 		t.Fatal(err)
 	}
 
+	// Try to create a file that includes a file in its path components.
+	// In *nix, this returns syscall.ENOTDIR while in windows we receive the following error.
 	err = fs.AppendFile("voldir", "/file/obj1", []byte("hello"))
 	winErr := "The system cannot find the path specified."
 	if !strings.Contains(err.Error(), winErr) {
 		t.Errorf("expected to recieve %s, but received %s", winErr, err.Error())
 	}
 }
+
+// Test to validate that path name in UNC form works
+func TestUNCPathDiskName(t *testing.T) {
+	var err error
+	// Instantiate posix object to manage a disk
+	longPathDisk := `\\?\c:\testdisk`
+	err = mkdirAll(longPathDisk, 0700)
+	if err != nil {
+		t.Fatal(err)
+	}
+	// Cleanup on exit of test
+	defer removeAll(longPathDisk)
+	var fs StorageAPI
+	fs, err = newPosix(longPathDisk)
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	// Create volume to use in conjunction with other StorageAPI's file API(s)
+	err = fs.MakeVol("voldir")
+	if err != nil {
+		t.Fatal(err)
+	}
+}
+
+// Test to validate 32k path works on windows platform
+func Test32kUNCPath(t *testing.T) {
+	var err error
+	// Instantiate posix object to manage a disk
+	longDiskName := `\\?\c:`
+	for {
+		compt := strings.Repeat("a", 255)
+		if len(compt)+len(longDiskName)+1 > 32767 {
+			break
+		}
+		longDiskName = longDiskName + `\` + compt
+	}
+
+	if len(longDiskName) < 32767 {
+		// The following calculation was derived empirically. It is not exactly MAX_PATH - len(longDiskName)
+		// possibly due to expansion rules as mentioned here -
+		// https://msdn.microsoft.com/en-us/library/windows/desktop/aa365247(v=vs.85).aspx#maxpath
+		remaining := 32767 - 25 - len(longDiskName)
+		longDiskName = longDiskName + `\` + strings.Repeat("a", remaining)
+	}
+	err = mkdirAll(longDiskName, 0700)
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	// Cleanup on exit of test
+	defer removeAll(longDiskName)
+	_, err = newPosix(longDiskName)
+	if err != nil {
+		t.Fatal(err)
+	}
+}