Fixed first byte of data blocks being cut off

Added GetSymlinkFileRecursive

datareader.go

@@ -175,12 +175,12 @@ func (d *dataReader) Read(p []byte) (int, error) {
 			d.curReadOffset = 0
 		}
 		for ; read < len(p); read++ {
-			d.curReadOffset++
 			if d.curReadOffset < len(d.curData) {
 				p[read] = d.curData[d.curReadOffset]
 			} else {
 				break
 			}
+			d.curReadOffset++
 		}
 	}
 	if read != len(p) {

file.go

@@ -229,7 +229,8 @@ func (f *File) SymlinkPath() string {
 	}
 }
 
-//GetSymlinkFile tries to return the squashfs.File associated with the symlink
+//GetSymlinkFile tries to return the squashfs.File associated with the symlink. If the file isn't a symlink
+//or the symlink points to a location outside the archive, nil is returned.
 func (f *File) GetSymlinkFile() *File {
 	if !f.IsSymlink() {
 		return nil
@@ -237,7 +238,28 @@ func (f *File) GetSymlinkFile() *File {
 	if strings.HasSuffix(f.SymlinkPath(), "/") {
 		return nil
 	}
-	return f.r.GetFileAtPath(f.SymlinkPath())
+	return f.Parent.GetFileAtPath(f.SymlinkPath())
+}
+
+//GetSymlinkFileRecursive tries to return the squasfs.File associated with the symlink. It will recursively
+//try to get the symlink's file. This will return either a non-symlink File, or nil.
+func (f *File) GetSymlinkFileRecursive() *File {
+	if !f.IsSymlink() {
+		return nil
+	}
+	if strings.HasSuffix(f.SymlinkPath(), "/") {
+		return nil
+	}
+	sym := f
+	for {
+		sym = sym.GetSymlinkFile()
+		if sym == nil {
+			return nil
+		}
+		if !sym.IsSymlink() {
+			return sym
+		}
+	}
 }
 
 //Mode returns the os.FileMode of the File. Sets mode bits for directories and symlinks.

squash_test.go

@@ -1,6 +1,7 @@
 package squashfs
 
 import (
+	"fmt"
 	"io"
 	"net/http"
 	"os"
@@ -12,10 +13,9 @@ import (
 const (
 	downloadURL  = "https://github.com/Swordfish90/cool-retro-term/releases/download/1.1.1/Cool-Retro-Term-1.1.1-x86_64.AppImage"
 	appImageName = "Cool-Retro-Term.AppImage"
-	squashfsName = "airootfs.sfs" //testing with a ArchLinux root fs from the live img
+	squashfsName = "balenaEtcher-1.5.113-x64.AppImage.sfs" //testing with a ArchLinux root fs from the live img
 )
 
-//Right now, don't use. Arch linux sfs uses XZ compression with filters, which isn't supported
 func TestSquashfs(t *testing.T) {
 	wd, err := os.Getwd()
 	if err != nil {
@@ -29,10 +29,20 @@ func TestSquashfs(t *testing.T) {
 	if err != nil {
 		t.Fatal(err)
 	}
-	os.RemoveAll(wd + "/testing/" + squashfsName + ".d")
-	root, _ := rdr.GetRootFolder()
-	errs := root.ExtractWithOptions(wd+"/testing/"+squashfsName+".d", false, false, os.ModePerm, true)
-	t.Fatal(errs)
+	fmt.Println("stuff", rdr.super.CompressionType)
+	fil := rdr.GetFileAtPath("*.desktop")
+	if fil == nil {
+		t.Fatal("Can't find desktop fil")
+	}
+	errs := fil.ExtractTo(wd + "/testing")
+	if len(errs) > 0 {
+		t.Fatal(errs)
+	}
+	errs = rdr.ExtractTo(wd + "/testing/" + squashfsName + ".d")
+	if len(errs) > 0 {
+		t.Fatal(errs)
+	}
+	t.Fatal("No Problems")
 }
 
 func TestAppImage(t *testing.T) {
@@ -78,7 +88,7 @@ func downloadTestAppImage(t *testing.T, dir string) {
 	}
 	defer appImage.Close()
 	check := http.Client{
-		CheckRedirect: func(r *http.Request, via []*http.Request) error {
+		CheckRedirect: func(r *http.Request, _ []*http.Request) error {
 			r.URL.Opaque = r.URL.Path
 			return nil
 		},