Bug #33768 --> add MakeUnqiue to nsIFile. this is actually dougt's code.

r=mscott

xpcom/io/nsDirectoryService.cpp

@@ -538,7 +538,21 @@ NS_IMETHODIMP
 nsDirectoryService::Get(const char* prop, const nsIID & uuid, void* *result)
 {
     nsStringKey key(prop);
-    if (!mHashtable->Exists(&key))
+    
+    nsCOMPtr<nsISupports> value = dont_AddRef(mHashtable->Get(&key));
+    
+    if (value)
+    {
+        nsCOMPtr<nsIFile> cloneFile;
+        nsCOMPtr<nsIFile> cachedFile = do_QueryInterface(value);
+        
+        if (!cachedFile)
+            return NS_ERROR_NULL_POINTER;
+
+        cachedFile->Clone(getter_AddRefs(cloneFile));
+        return cloneFile->QueryInterface(uuid, result);
+    }
+    else
     {
       // it is not one of our defaults, lets check any providers
       FileData fileData;
@@ -550,32 +564,16 @@ nsDirectoryService::Get(const char* prop, const nsIID & uuid, void* *result)
       
       if (fileData.file)
       {
-        if (!fileData.persistant)
+        if (fileData.persistant)
 		{
-			nsresult rv = (fileData.file)->QueryInterface(uuid, result);
-			NS_RELEASE(fileData.file);
-			return rv;
+			Set(prop, NS_STATIC_CAST(nsIFile*, fileData.file));
 		}
-		Set(prop, NS_STATIC_CAST(nsIFile*, fileData.file));
-        NS_RELEASE(fileData.file);
+        nsresult rv = (fileData.file)->QueryInterface(uuid, result);
+		NS_RELEASE(fileData.file);  // addref occurs in FindProviderFile()
+		return rv;
       } 
     }
 
-    
-    // now check again to see if it was added above.
-    if (mHashtable->Exists(&key))
-    {
-      nsCOMPtr<nsIFile> ourFile;
-      nsCOMPtr<nsISupports> value = getter_AddRefs (mHashtable->Get(&key));
-      
-      if (value && NS_SUCCEEDED(value->QueryInterface(NS_GET_IID(nsIFile), getter_AddRefs(ourFile))))
-      {
-        nsCOMPtr<nsIFile> cloneFile;
-        ourFile->Clone(getter_AddRefs(cloneFile));
-        return cloneFile->QueryInterface(uuid, result);
-      }
-    }
-
     return NS_ERROR_FAILURE;
 }
 
@@ -593,7 +591,7 @@ nsDirectoryService::Set(const char* prop, nsISupports* value)
       nsCOMPtr<nsIFile> cloneFile;
       ourFile->Clone (getter_AddRefs (cloneFile));
       mHashtable->Put(&key, cloneFile);
-        return NS_OK;
+      return NS_OK;
     }
     return NS_ERROR_FAILURE;   
 }

xpcom/io/nsIFile.idl

@@ -230,6 +230,12 @@ interface nsIFile : nsISupports
      */
     boolean isSpecial();
 
+    /**
+     * .
+     */
+    void makeUnique(in string suggestedName);
+    
+
     /**
       * clone()
       *
@@ -258,7 +264,7 @@ interface nsIFile : nsISupports
      * Parent will be nsnull when this is at the top of the volume.
      */
     readonly attribute nsIFile parent;
-
+    
     /**
      * Returns an enumeration of the elements in a directory. Each
      * element in the enumeration is an nsIFile.

xpcom/io/nsLocalFileCommon.cpp

@@ -367,3 +367,49 @@ nsresult nsFileSpec::Execute(const nsString& args) const
   SET_UCS( Execute , args.GetUnicode());
 }
 
+// should work on Macintosh, Unix, and Win32.
+#define kMaxFilenameLength 31  
+
+
+NS_IMETHODIMP
+nsLocalFile::MakeUnique(const char* suggestedName)
+{
+    PRBool exists;
+    nsresult rv = Exists(&exists);
+    
+    if (NS_FAILED(rv)) return rv;
+    if (!exists) return NS_OK;
+
+    char* leafName; 
+    rv = GetLeafName(&leafName);
+
+    if (NS_FAILED(rv)) return rv;
+
+    char* lastDot = strrchr(leafName, '.');
+    char* suffix = "";
+    if (lastDot)
+    {
+        suffix = nsCRT::strdup(lastDot); // include '.'
+        *lastDot = '\0'; // strip suffix and dot.
+    }
+
+    // 27 should work on Macintosh, Unix, and Win32. 
+    const int maxRootLength = 27 - nsCRT::strlen(suffix) - 1;
+
+    if ((int)nsCRT::strlen(leafName) > (int)maxRootLength)
+        leafName[maxRootLength] = '\0';
+
+    for (short indx = 1; indx < 10000 && exists; indx++)
+    {
+        // start with "Picture-1.jpg" after "Picture.jpg" exists
+        char newName[kMaxFilenameLength + 1];
+        sprintf(newName, "%s-%d%s", leafName, indx, suffix);
+        SetLeafName(newName);
+
+        rv = Exists(&exists);
+        if (NS_FAILED(rv)) return rv;
+    }
+    return NS_OK;
+}
+
+