Fix more bugs when reusing FileReaders for multiple reads. Also fix leaks. r=jst a=jst

content/base/src/nsDOMFileReader.cpp

@@ -167,6 +167,8 @@ nsDOMFileReader::~nsDOMFileReader()
   if (mListenerManager) 
     mListenerManager->Disconnect();
 
+  FreeFileData();
+
   nsLayoutStatics::Release();
 }
 
@@ -309,9 +311,7 @@ nsDOMFileReader::Abort()
   mFile = nsnull;
 
   //Clean up memory buffer
-  PR_Free(mFileData);
-  mFileData = nsnull;
-  mDataLen = 0;
+  FreeFileData();
 
   //Dispatch the abort event
   DispatchProgressEvent(NS_LITERAL_STRING(ABORT_STR));
@@ -449,6 +449,7 @@ nsDOMFileReader::OnStopRequest(nsIRequest *aRequest,
 
   //Set the status field as appropriate
   if (NS_FAILED(aStatus)) {
+    FreeFileData();
     DispatchError(aStatus);
     return NS_OK;
   }
@@ -467,6 +468,8 @@ nsDOMFileReader::OnStopRequest(nsIRequest *aRequest,
      return NS_ERROR_FAILURE;
   }
 
+  FreeFileData();
+
   //Dispatch load event to signify end of a successful load
   DispatchProgressEvent(NS_LITERAL_STRING(LOAD_STR));
   DispatchProgressEvent(NS_LITERAL_STRING(LOADEND_STR));
@@ -485,11 +488,15 @@ nsDOMFileReader::ReadFileContent(nsIDOMFile* aFile,
 
   //Implicit abort to clear any other activity going on
   Abort();
-  mDataFormat = aDataFormat;
-  mCharset = aCharset;
   mError = nsnull;
   SetDOMStringToNull(mResult);
   mReadTransferred = 0;
+  mReadTotal = 0;
+  mReadyState = nsIDOMFileReader::EMPTY;
+  FreeFileData();
+
+  mDataFormat = aDataFormat;
+  mCharset = aCharset;
 
   //Obtain the nsDOMFile's underlying nsIFile
   nsresult rv;

content/base/src/nsDOMFileReader.h

@@ -60,6 +60,7 @@
 #include "nsCOMPtr.h"
 #include "nsIStreamLoader.h"
 #include "nsIChannel.h"
+#include "prmem.h"
 
 #include "nsXMLHttpRequest.h"
 
@@ -119,6 +120,12 @@ protected:
   void DispatchError(nsresult rv);
   void StartProgressEventTimer();
 
+  void FreeFileData() {
+    PR_Free(mFileData);
+    mFileData = nsnull;
+    mDataLen = 0;
+  }
+
   char *mFileData;
   nsCOMPtr<nsIFile> mFile;
   nsString mCharset;

content/base/test/test_fileapi.html

@@ -126,17 +126,49 @@ expectedTestCount++;
 r = new FileReader();
 r.onload = getLoadHandler(testASCIIData,
                           testASCIIData.length,
-                          "to-be-reused reading")
+                          "to-be-reused reading text")
 var makeAnotherReadListener = function(event) {
   r = event.target;
   r.removeEventListener("load", makeAnotherReadListener, false);
-  r.onload = getLoadHandler(testBinaryData,
-                            testBinaryData.length,
-                            "reused reading");
-  r.readAsBinaryString(binaryFile);
+  r.onload = getLoadHandler(testASCIIData,
+                            testASCIIData.length,
+                            "reused reading text");
+  r.readAsText(asciiFile);
 };
 r.addEventListener("load", makeAnotherReadListener, false);
-r.readAsText(asciiFile, "");
+r.readAsText(asciiFile);
+expectedTestCount += 2;
+
+r = new FileReader();
+r.onload = getLoadHandler(testBinaryData,
+                          testBinaryData.length,
+                          "to-be-reused reading binary")
+var makeAnotherReadListener2 = function(event) {
+  r = event.target;
+  r.removeEventListener("load", makeAnotherReadListener2, false);
+  r.onload = getLoadHandler(testBinaryData,
+                            testBinaryData.length,
+                            "reused reading binary");
+  r.readAsBinaryString(binaryFile);
+};
+r.addEventListener("load", makeAnotherReadListener2, false);
+r.readAsBinaryString(binaryFile);
+expectedTestCount += 2;
+
+r = new FileReader();
+r.onload = getLoadHandler(convertToDataURL(testBinaryData),
+                          testBinaryData.length,
+                          "to-be-reused reading data url")
+var makeAnotherReadListener3 = function(event) {
+  r = event.target;
+  r.removeEventListener("load", makeAnotherReadListener3, false);
+  r.onload = getLoadHandler(convertToDataURL(testBinaryData),
+                            testBinaryData.length,
+                            "reused reading data url");
+  r.readAsDataURL(binaryFile);
+};
+r.addEventListener("load", makeAnotherReadListener3, false);
+r.readAsDataURL(binaryFile);
 expectedTestCount += 2;