fix: delete the previous content when a file is replaced

internal/storage/FileServing.go

@@ -384,6 +384,7 @@ func ReplaceFile(fileId, newFileContentId string, delete bool) (models.File, err
 		return models.File{}, ErrorReplaceE2EFile
 	}
 
+	previousContent := file
 	file.Name = newFileContent.Name
 	file.Size = newFileContent.Size
 	file.SHA1 = newFileContent.SHA1
@@ -392,12 +393,27 @@ func ReplaceFile(fileId, newFileContentId string, delete bool) (models.File, err
 	file.SizeBytes = newFileContent.SizeBytes
 	file.Encryption = newFileContent.Encryption
 	database.SaveMetaData(file)
+	deleteUnreferencedSource(previousContent)
 	if delete {
 		DeleteFile(newFileContent.Id, true)
 	}
 	return file, nil
 }
 
+// deleteUnreferencedSource deletes the stored data of a file that no metadata entry points at anymore.
+// CleanUp only reaches sources that are still referenced by an entry, so the content a replaced file
+// used to hold would otherwise stay in storage for good.
+func deleteUnreferencedSource(file models.File) {
+	for _, metadata := range database.GetAllMetadata() {
+		if metadata.SHA1 == file.SHA1 {
+			return
+		}
+	}
+	if FileExists(file, configuration.Get().DataDir) {
+		deleteSource(file, configuration.Get().DataDir)
+	}
+}
+
 func isChangeRequested(parametersToChange, parameter int) bool {
 	return parametersToChange&parameter != 0
 }

internal/storage/FileServing_test.go

@@ -895,6 +895,44 @@ func TestReplaceFile(t *testing.T) {
 	_, ok = GetFile(newFile.Id)
 	test.IsEqualBool(t, ok, false)
 }
+func TestReplaceFileDeletesPreviousContent(t *testing.T) {
+	dataDir := configuration.Get().DataDir
+	previousSha1 := "replacedoldcontent"
+	newSha1 := "replacednewcontent"
+	test.IsNil(t, os.WriteFile(dataDir+"/"+previousSha1, []byte("old"), 0600))
+	test.IsNil(t, os.WriteFile(dataDir+"/"+newSha1, []byte("new"), 0600))
+
+	original := models.File{
+		Id:                 "replacesourceoriginal",
+		Name:               "old.txt",
+		Size:               "3 B",
+		SHA1:               previousSha1,
+		ContentType:        "text/plain",
+		UnlimitedDownloads: true,
+		UnlimitedTime:      true,
+		SizeBytes:          3,
+	}
+	replacement := models.File{
+		Id:                 "replacesourcenew",
+		Name:               "new.txt",
+		Size:               "3 B",
+		SHA1:               newSha1,
+		ContentType:        "text/plain",
+		UnlimitedDownloads: true,
+		UnlimitedTime:      true,
+		SizeBytes:          3,
+	}
+	database.SaveMetaData(original)
+	database.SaveMetaData(replacement)
+
+	_, err := ReplaceFile(original.Id, replacement.Id, false)
+	test.IsNil(t, err)
+
+	_, err = os.Stat(dataDir + "/" + previousSha1)
+	test.IsEqualBool(t, os.IsNotExist(err), true)
+	test.FileExists(t, dataDir+"/"+newSha1)
+}
+
 func TestParallelDownloads(t *testing.T) {
 	const allowedDownloads = 5