Bug 1746052, use ValidateFileNameForSaving to determine a valid filename for pasting a file to the filesystem, r=smaug

Differential Revision: https://phabricator.services.mozilla.com/D135953

dom/base/nsCopySupport.cpp

@@ -32,8 +32,6 @@
 #include "nsHTMLDocument.h"
 #include "nsGkAtoms.h"
 #include "nsIFrame.h"
-#include "nsIURI.h"
-#include "nsGenericHTMLElement.h"
 
 // image copy stuff
 #include "nsIImageLoadingContent.h"
@@ -604,70 +602,39 @@ static nsresult AppendImagePromise(nsITransferable* aTransferable,
   nsCOMPtr<nsINode> node = do_QueryInterface(aImageElement, &rv);
   NS_ENSURE_SUCCESS(rv, rv);
 
-  // Fix the file extension in the URL if necessary
-  nsCOMPtr<nsIMIMEService> mimeService =
-      do_GetService(NS_MIMESERVICE_CONTRACTID);
-  NS_ENSURE_TRUE(mimeService, NS_OK);
+  nsCOMPtr<nsIMIMEService> mimeService = do_GetService("@mozilla.org/mime;1");
+  if (NS_WARN_IF(!mimeService)) {
+    return NS_ERROR_FAILURE;
+  }
 
   nsCOMPtr<nsIURI> imgUri;
   rv = aImgRequest->GetFinalURI(getter_AddRefs(imgUri));
   NS_ENSURE_SUCCESS(rv, rv);
 
-  nsCOMPtr<nsIURL> imgUrl = do_QueryInterface(imgUri);
-  NS_ENSURE_TRUE(imgUrl, NS_OK);
-
-  nsAutoCString extension;
-  rv = imgUrl->GetFileExtension(extension);
-  NS_ENSURE_SUCCESS(rv, rv);
-
-  nsCString mimeType;
-  rv = aImgRequest->GetMimeType(getter_Copies(mimeType));
-  NS_ENSURE_SUCCESS(rv, rv);
-
-  nsCOMPtr<nsIMIMEInfo> mimeInfo;
-  mimeService->GetFromTypeAndExtension(mimeType, ""_ns,
-                                       getter_AddRefs(mimeInfo));
-  NS_ENSURE_TRUE(mimeInfo, NS_OK);
-
   nsAutoCString spec;
-  rv = imgUrl->GetSpec(spec);
+  rv = imgUri->GetSpec(spec);
   NS_ENSURE_SUCCESS(rv, rv);
 
   // pass out the image source string
   nsString imageSourceString;
   CopyUTF8toUTF16(spec, imageSourceString);
 
-  bool validExtension;
-  if (extension.IsEmpty() ||
-      NS_FAILED(mimeInfo->ExtensionExists(extension, &validExtension)) ||
-      !validExtension) {
-    // Fix the file extension in the URL
-    nsAutoCString primaryExtension;
-    mimeInfo->GetPrimaryExtension(primaryExtension);
-    if (!primaryExtension.IsEmpty()) {
-      rv = NS_MutateURI(imgUri)
-               .Apply(&nsIURLMutator::SetFileExtension, primaryExtension,
-                      nullptr)
-               .Finalize(imgUrl);
-      NS_ENSURE_SUCCESS(rv, rv);
-    }
-  }
+  nsCString mimeType;
+  rv = aImgRequest->GetMimeType(getter_Copies(mimeType));
+  NS_ENSURE_SUCCESS(rv, rv);
 
   nsAutoCString fileName;
-  imgUrl->GetFileName(fileName);
+  rv = aImgRequest->GetFileName(fileName);
+  NS_ENSURE_SUCCESS(rv, rv);
 
-  NS_UnescapeURL(fileName);
-
-  // make the filename safe for the filesystem
-  fileName.ReplaceChar(FILE_PATH_SEPARATOR FILE_ILLEGAL_CHARACTERS, '-');
-
-  nsString imageDestFileName;
-  CopyUTF8toUTF16(fileName, imageDestFileName);
+  nsAutoString validFileName = NS_ConvertUTF8toUTF16(fileName);
+  mimeService->ValidateFileNameForSaving(
+      validFileName, mimeType, nsIMIMEService::VALIDATE_DEFAULT, validFileName);
 
   rv = AppendString(aTransferable, imageSourceString, kFilePromiseURLMime);
   NS_ENSURE_SUCCESS(rv, rv);
 
-  rv = AppendString(aTransferable, imageDestFileName, kFilePromiseDestFilename);
+  rv = AppendString(aTransferable, validFileName, kFilePromiseDestFilename);
   NS_ENSURE_SUCCESS(rv, rv);
 
   aTransferable->SetRequestingPrincipal(node->NodePrincipal());