Bug 122892: nsLocalFile::Clone should preserve stat info.

make nsLocalFile* impls use copy constructors for their nsIFile::Clone methods.
This avoids unnecessary |stat| calls inherent in using NS_NewNativeLocalFile.

b=122892, r=dougt, sr=darin, with many thanks to biesi & mkaply for testing on other
plats.

xpcom/io/nsLocalFileMac.cpp

@@ -1084,15 +1084,11 @@ nsLocalFile::ResolveAndStat()
 NS_IMETHODIMP  
 nsLocalFile::Clone(nsIFile **file)
 {
-    NS_ENSURE_ARG(file);
-    *file = nsnull;
-    
     // Just copy-construct ourselves
-    nsCOMPtr<nsILocalFile> localFile = new nsLocalFile(*this);
-    if (localFile == NULL)
+    *file = new nsLocalFile(*this);
+    if (!*file)
       return NS_ERROR_OUT_OF_MEMORY;
 
-    *file = localFile;
     NS_ADDREF(*file);
     
     return NS_OK;

xpcom/io/nsLocalFileOS2.cpp

@@ -250,6 +250,13 @@ nsLocalFile::nsLocalFile()
     MakeDirty();
 }
 
+nsLocalFile::nsLocalFile(const nsLocalFile& other)
+  : mDirty(other.mDirty)
+  , mWorkingPath(other.mWorkingPath)
+  , mFileInfo64(other.mFileInfo64)
+{
+}
+
 nsLocalFile::~nsLocalFile()
 {
 }
@@ -313,18 +320,14 @@ nsLocalFile::Stat()
 NS_IMETHODIMP  
 nsLocalFile::Clone(nsIFile **file)
 {
-    nsresult rv;
+    // Just copy-construct ourselves
+    *file = new nsLocalFile(*this);
+    if (!*file)
+      return NS_ERROR_OUT_OF_MEMORY;
 
-    nsCOMPtr<nsILocalFile> localFile;
-
-    rv = NS_NewNativeLocalFile(mWorkingPath, PR_TRUE, getter_AddRefs(localFile));
+    NS_ADDREF(*file);
     
-    if (NS_SUCCEEDED(rv) && localFile)
-    {
-        return localFile->QueryInterface(NS_GET_IID(nsIFile), (void**)file);
-    }
-            
-    return rv;
+    return NS_OK;
 }
 
 NS_IMETHODIMP  

xpcom/io/nsLocalFileOS2.h

@@ -79,6 +79,7 @@ public:
     static void GlobalShutdown();
 
 private:
+    nsLocalFile(const nsLocalFile& other);
 
     // this is the flag which indicates if I can used cached information about the file
     PRPackedBool mDirty;

xpcom/io/nsLocalFileOSX.cpp

@@ -997,13 +997,11 @@ NS_IMETHODIMP nsLocalFile::IsSpecial(PRBool *_retval)
 /* nsIFile clone (); */
 NS_IMETHODIMP nsLocalFile::Clone(nsIFile **_retval)
 {
-    NS_ENSURE_ARG_POINTER(_retval);
-    *_retval = nsnull;
-    
-    nsLocalFile *newFile = new nsLocalFile(*this);
-    if (!newFile)
-        return NS_ERROR_OUT_OF_MEMORY;
-    *_retval = newFile;
+    // Just copy-construct ourselves
+    *_retval = new nsLocalFile(*this);
+    if (!*_retval)
+      return NS_ERROR_OUT_OF_MEMORY;
+
     NS_ADDREF(*_retval);
     
     return NS_OK;

xpcom/io/nsLocalFileUnix.cpp

@@ -201,6 +201,13 @@ nsLocalFile::nsLocalFile() :
 {
 }
 
+nsLocalFile::nsLocalFile(const nsLocalFile& other)
+  : mCachedStat(other.mCachedStat)
+  , mPath(other.mPath)
+  , mHaveCachedStat(other.mHaveCachedStat)
+{
+}
+
 nsLocalFile::~nsLocalFile()
 {
 }
@@ -240,18 +247,13 @@ nsLocalFile::FillStatCache() {
 NS_IMETHODIMP
 nsLocalFile::Clone(nsIFile **file)
 {
-    NS_ENSURE_ARG(file);
+    // Just copy-construct ourselves
+    *file = new nsLocalFile(*this);
+    if (!*file)
+      return NS_ERROR_OUT_OF_MEMORY;
 
-    nsLocalFile* localFile = new nsLocalFile();
-    if (!localFile)
-        return NS_ERROR_OUT_OF_MEMORY;
-
-    nsresult rv = localFile->InitWithNativePath(mPath);
-    if (NS_FAILED(rv))
-        return rv;
-
-    *file = NS_STATIC_CAST(nsIFile *, localFile);
     NS_ADDREF(*file);
+    
     return NS_OK;
 }
 

xpcom/io/nsLocalFileUnix.h

@@ -87,6 +87,9 @@ public:
     static void GlobalInit();
     static void GlobalShutdown();
 
+private:
+    nsLocalFile(const nsLocalFile& other);
+
 protected:
     struct stat  mCachedStat;
     nsCString    mPath;

xpcom/io/nsLocalFileWin.cpp

@@ -438,6 +438,16 @@ NS_IMPL_THREADSAFE_ISUPPORTS2(nsLocalFile, nsILocalFile, nsIFile)
 // nsLocalFile <private>
 //-----------------------------------------------------------------------------
 
+nsLocalFile::nsLocalFile(const nsLocalFile& other)
+  : mDirty(other.mDirty)
+  , mLastResolution(other.mLastResolution)
+  , mFollowSymlinks(other.mFollowSymlinks)
+  , mWorkingPath(other.mWorkingPath)
+  , mResolvedPath(other.mResolvedPath)
+  , mFileInfo64(other.mFileInfo64)
+{
+}
+
 // This function resets any cached information about the file.
 void
 nsLocalFile::MakeDirty()
@@ -693,21 +703,13 @@ nsLocalFile::ResolveAndStat(PRBool resolveTerminal)
 NS_IMETHODIMP  
 nsLocalFile::Clone(nsIFile **file)
 {
-    NS_ENSURE_ARG(file);
-    *file = nsnull;
-    
     // Just copy-construct ourselves
-    nsLocalFile *localFile = new nsLocalFile(*this);
-    if (localFile == NULL)
-        return NS_ERROR_OUT_OF_MEMORY;
+    *file = new nsLocalFile(*this);
+    if (!*file)
+      return NS_ERROR_OUT_OF_MEMORY;
 
-    // don't forget to re-initialize mRefCnt
-    // or the new object will have the old refcnt
-    localFile->mRefCnt = 0;
-    
-    *file = localFile;
     NS_ADDREF(*file);
-        
+    
     return NS_OK;
 }
 

xpcom/io/nsLocalFileWin.h

@@ -68,6 +68,7 @@ public:
     static void GlobalShutdown();
 
 private:
+    nsLocalFile(const nsLocalFile& other);
 
     // this is the flag which indicates if I can used cached information about the file
     PRPackedBool mDirty;