From 8f099fcd2713d27b80e00dfbddfddaa38a16f50b Mon Sep 17 00:00:00 2001
From: lordwelch <timmy@narnian.us>
Date: Mon, 15 Feb 2021 21:30:46 -0800
Subject: [PATCH] Add error handling for decompression

---
 binutils.go | 18 +++++++++---------
 lsf/lsf.go  | 20 ++++++++++++++++----
 2 files changed, 25 insertions(+), 13 deletions(-)

diff --git a/binutils.go b/binutils.go
index 574f175..bde1476 100644
--- a/binutils.go
+++ b/binutils.go
@@ -82,18 +82,18 @@ func MakeCompressionFlags(method CompressionMethod, level CompressionLevel) int
 	return flags | int(level)
 }
 
-func Decompress(compressed io.Reader, uncompressedSize int, compressionFlags byte, chunked bool) io.ReadSeeker {
+func Decompress(compressed io.Reader, uncompressedSize int, compressionFlags byte, chunked bool) (io.ReadSeeker, error) {
 	switch CompressionMethod(compressionFlags & 0x0f) {
 	case CMNone:
 		if v, ok := compressed.(io.ReadSeeker); ok {
-			return v
+			return v, nil
 		}
-		panic(errors.New("compressed must be an io.ReadSeeker if there is no compression"))
+		return nil, errors.New("compressed must be an io.ReadSeeker if there is no compression")
 
 	case CMZlib:
 		zr, _ := zlib.NewReader(compressed)
 		v, _ := ioutil.ReadAll(zr)
-		return bytes.NewReader(v)
+		return bytes.NewReader(v), nil
 
 	case CMLZ4:
 		if chunked {
@@ -101,21 +101,21 @@ func Decompress(compressed io.Reader, uncompressedSize int, compressionFlags byt
 			p := make([]byte, uncompressedSize)
 			_, err := zr.Read(p)
 			if err != nil {
-				panic(err)
+				return nil, err
 			}
-			return bytes.NewReader(p)
+			return bytes.NewReader(p), nil
 		}
 		src, _ := ioutil.ReadAll(compressed)
 		dst := make([]byte, uncompressedSize*2)
 		_, err := lz4.UncompressBlock(src, dst)
 		if err != nil {
-			panic(err)
+			return nil, err
 		}
 
-		return bytes.NewReader(dst)
+		return bytes.NewReader(dst), nil
 
 	default:
-		panic(fmt.Errorf("no decompressor found for this format: %v", compressionFlags))
+		return nil, fmt.Errorf("no decompressor found for this format: %v", compressionFlags)
 	}
 }
 
diff --git a/lsf/lsf.go b/lsf/lsf.go
index c29b8c1..16ed538 100644
--- a/lsf/lsf.go
+++ b/lsf/lsf.go
@@ -678,7 +678,10 @@ func Read(r io.ReadSeeker) (lsgo.Resource, error) {
 		uncompressed := lsgo.LimitReadSeeker(r, int64(hdr.StringsSizeOnDisk))
 
 		if isCompressed {
-			uncompressed = lsgo.Decompress(uncompressed, int(hdr.StringsUncompressedSize), hdr.CompressionFlags, false)
+			uncompressed, err = lsgo.Decompress(uncompressed, int(hdr.StringsUncompressedSize), hdr.CompressionFlags, false)
+			if err != nil {
+				return lsgo.Resource{}, fmt.Errorf("decompressing LSF name failed: %w", err)
+			}
 		}
 
 		// using (var nodesFile = new FileStream("names.bin", FileMode.Create, FileAccess.Write))
@@ -703,7 +706,10 @@ func Read(r io.ReadSeeker) (lsgo.Resource, error) {
 	if hdr.NodesSizeOnDisk > 0 || hdr.NodesUncompressedSize > 0 {
 		uncompressed := lsgo.LimitReadSeeker(r, int64(hdr.NodesSizeOnDisk))
 		if isCompressed {
-			uncompressed = lsgo.Decompress(uncompressed, int(hdr.NodesUncompressedSize), hdr.CompressionFlags, hdr.Version >= lsgo.VerChunkedCompress)
+			uncompressed, err = lsgo.Decompress(uncompressed, int(hdr.NodesUncompressedSize), hdr.CompressionFlags, hdr.Version >= lsgo.VerChunkedCompress)
+			if err != nil {
+				return lsgo.Resource{}, fmt.Errorf("decompressing LSF nodes failed: %w", err)
+			}
 		}
 
 		// using (var nodesFile = new FileStream("nodes.bin", FileMode.Create, FileAccess.Write))
@@ -729,7 +735,10 @@ func Read(r io.ReadSeeker) (lsgo.Resource, error) {
 	if hdr.AttributesSizeOnDisk > 0 || hdr.AttributesUncompressedSize > 0 {
 		var uncompressed io.ReadSeeker = lsgo.LimitReadSeeker(r, int64(hdr.AttributesSizeOnDisk))
 		if isCompressed {
-			uncompressed = lsgo.Decompress(uncompressed, int(hdr.AttributesUncompressedSize), hdr.CompressionFlags, hdr.Version >= lsgo.VerChunkedCompress)
+			uncompressed, err = lsgo.Decompress(uncompressed, int(hdr.AttributesUncompressedSize), hdr.CompressionFlags, hdr.Version >= lsgo.VerChunkedCompress)
+			if err != nil {
+				return lsgo.Resource{}, fmt.Errorf("decompressing LSF attributes failed: %w", err)
+			}
 		}
 
 		// using (var attributesFile = new FileStream("attributes.bin", FileMode.Create, FileAccess.Write))
@@ -752,7 +761,10 @@ func Read(r io.ReadSeeker) (lsgo.Resource, error) {
 	var uncompressed io.ReadSeeker = lsgo.LimitReadSeeker(r, int64(hdr.ValuesSizeOnDisk))
 	if hdr.ValuesSizeOnDisk > 0 || hdr.ValuesUncompressedSize > 0 {
 		if isCompressed {
-			uncompressed = lsgo.Decompress(r, int(hdr.ValuesUncompressedSize), hdr.CompressionFlags, hdr.Version >= lsgo.VerChunkedCompress)
+			uncompressed, err = lsgo.Decompress(r, int(hdr.ValuesUncompressedSize), hdr.CompressionFlags, hdr.Version >= lsgo.VerChunkedCompress)
+			if err != nil {
+				return lsgo.Resource{}, fmt.Errorf("decompressing LSF values failed: %w", err)
+			}
 		}
 	}