From b386489b1a1fb752c68b4011eba3c5f9c6686ae9 Mon Sep 17 00:00:00 2001
From: Pagran <67878280+pagran@users.noreply.github.com>
Date: Tue, 20 Oct 2020 01:05:43 +0300
Subject: [PATCH] Add test Add comment Debug dir cleanup

---
 import_obfuscation.go         | 80 ++++++++++++++++++++---------------
 main.go                       |  9 ++--
 testdata/scripts/debugdir.txt | 10 +++++
 3 files changed, 59 insertions(+), 40 deletions(-)

diff --git a/import_obfuscation.go b/import_obfuscation.go
index ea1aa30..7fddad6 100644
--- a/import_obfuscation.go
+++ b/import_obfuscation.go
@@ -71,56 +71,66 @@ func extractDebugObfSrc(pkgPath string, pkg *goobj2.Package) error {
 	if envGarbleDebugDir == "" {
 		return nil
 	}
+
+	var archiveMember *goobj2.ArchiveMember
 	for _, member := range pkg.ArchiveMembers {
-		if member.ArchiveHeader.Name != garbleSrcHeaderName {
-			continue
+		if member.ArchiveHeader.Name == garbleSrcHeaderName {
+			archiveMember = &member
+			break
 		}
+	}
 
-		osPkgPath := filepath.FromSlash(pkgPath)
-		pkgDebugDir := filepath.Join(envGarbleDebugDir, osPkgPath)
-		if err := os.MkdirAll(pkgDebugDir, 0o755); err != nil {
-			return err
-		}
+	if archiveMember == nil {
+		return nil
+	}
 
-		archiveSize, err := strconv.Atoi(member.ArchiveHeader.Date)
+	osPkgPath := filepath.FromSlash(pkgPath)
+	pkgDebugDir := filepath.Join(envGarbleDebugDir, osPkgPath)
+	if err := os.MkdirAll(pkgDebugDir, 0o755); err != nil {
+		return err
+	}
+
+	archiveSize, err := strconv.Atoi(archiveMember.ArchiveHeader.Date)
+	if err != nil {
+		return err
+	}
+
+	archiveBytes := archiveMember.ArchiveHeader.Data[:archiveSize]
+
+	archive := bytes.NewBuffer(archiveBytes)
+	gzipReader, err := gzip.NewReader(archive)
+	if err != nil {
+		return err
+	}
+	defer gzipReader.Close()
+	tarReader := tar.NewReader(gzipReader)
+
+	for {
+		header, err := tarReader.Next()
+		if err == io.EOF {
+			return nil
+		}
 		if err != nil {
 			return err
 		}
 
-		archiveBytes := member.ArchiveHeader.Data[:archiveSize]
-
-		archive := bytes.NewBuffer(archiveBytes)
-		gzipReader, err := gzip.NewReader(archive)
+		debugFilePath := filepath.Join(pkgDebugDir, header.Name)
+		debugFile, err := os.Create(debugFilePath)
 		if err != nil {
 			return err
 		}
-		defer gzipReader.Close()
-		tarReader := tar.NewReader(gzipReader)
-
-		for {
-			header, err := tarReader.Next()
-			if err == io.EOF {
-				return nil
-			}
-			if err != nil {
-				return err
-			}
+		if _, err := io.Copy(debugFile, tarReader); err != nil {
+			return err
+		}
+		debugFile.Close()
 
-			debugFilePath := filepath.Join(pkgDebugDir, header.Name)
-			debugFile, err := os.Create(debugFilePath)
-			if err != nil {
-				return err
-			}
-			if _, err := io.Copy(debugFile, tarReader); err != nil {
-				return err
-			}
-			debugFile.Close()
+		obfuscationTime := header.ModTime.Local()
 
-			obfuscationTime := header.ModTime.Local()
-			os.Chtimes(debugFilePath, obfuscationTime, obfuscationTime) // Restore obfuscation time
+		// Restore the actual source obfuscation time so as not to mislead the user.
+		if err := os.Chtimes(debugFilePath, obfuscationTime, obfuscationTime); err != nil {
+			return err
 		}
 	}
-	return nil
 }
 
 // obfuscateImports does all the necessary work to replace the import paths of
diff --git a/main.go b/main.go
index c6cd566..63d85b2 100644
--- a/main.go
+++ b/main.go
@@ -359,15 +359,13 @@ func mainErr(args []string) error {
 				flagDebugDir = filepath.Join(wd, flagDebugDir)
 			}
 
-			if info, err := os.Stat(flagDebugDir); os.IsNotExist(err) {
+			if err := os.RemoveAll(flagDebugDir); err == nil || os.IsNotExist(err) {
 				err := os.MkdirAll(flagDebugDir, 0o755)
 				if err != nil {
 					return err
 				}
-			} else if err != nil {
+			} else {
 				return fmt.Errorf("debugdir error: %v", err)
-			} else if !info.IsDir() {
-				return fmt.Errorf("debugdir exists, but is a file not a directory")
 			}
 		}
 
@@ -781,7 +779,8 @@ func transformCompile(args []string) ([]string, error) {
 			ArchiveHeader: goobj2.ArchiveHeader{
 				Name: garbleSrcHeaderName,
 				Size: int64(obfSrcArchive.Len()),
-				Date: strconv.Itoa(obfSrcArchive.Len()), // Zero byte bug bypass
+				// Work around https://github.com/Binject/debug/issues/14
+				Date: strconv.Itoa(obfSrcArchive.Len()),
 				Data: obfSrcArchive.Bytes(),
 			},
 		})
diff --git a/testdata/scripts/debugdir.txt b/testdata/scripts/debugdir.txt
index 03a0c34..164d3ad 100644
--- a/testdata/scripts/debugdir.txt
+++ b/testdata/scripts/debugdir.txt
@@ -1,4 +1,6 @@
 env GOPRIVATE=test/main
+# Isolate go cache for test reproducibility
+env GOCACHE=$WORK/.temp-cache
 
 garble -debugdir ./test1 build
 exists 'test1/test/main/imported/imported.go' 'test1/main/main.go'
@@ -6,6 +8,14 @@ exists 'test1/test/main/imported/imported.go' 'test1/main/main.go'
 ! grep ImportedFunc $WORK/test1/main/main.go
 ! grep 'some comment' $WORK/test1/main/main.go
 
+[short] stop
+
+cp $WORK/test1/main/main.go $WORK/test1/some_file_from_prev_build.go
+
+garble -debugdir ./test1 build -v
+! stderr 'test/main'
+! exists $WORK/test1/some_file_from_prev_build.go
+
 -- go.mod --
 module test/main
 -- main.go --