Open/save dialog assumes the defaultPath parameter without '/' as a default file name.

chrome/browser/resources/file_manager/js/file_manager.js

Index: chrome/browser/resources/file_manager/js/file_manager.js
diff --git a/chrome/browser/resources/file_manager/js/file_manager.js b/chrome/browser/resources/file_manager/js/file_manager.js
index 4b66f4c7a9d6ce9948d02e8789d32c29eb1e58ac..a54de57b1bc9b8d90a1bc43dfe82ffd1bdd527d3 100644
--- a/chrome/browser/resources/file_manager/js/file_manager.js
+++ b/chrome/browser/resources/file_manager/js/file_manager.js
@@ -19,9 +19,6 @@ function FileManager(dialogDom) {
   this.params_ = location.search ?
                  JSON.parse(decodeURIComponent(location.search.substr(1))) :
                  {};
-  if (this.params_.defaultPath && this.params_.defaultPath.indexOf('/') != 0)

[dgozman, 2012/07/02 12:38:47]

Sometimes save-as dialog is called with 'drive/folder/file.name' as a parameter,
and this will break it.

-    this.params_.defaultPath = '/' + this.params_.defaultPath;
-
   this.listType_ = null;
   this.showDelayTimeout_ = null;
 
@@ -1074,10 +1071,10 @@ FileManager.prototype = {
       // Hack goes below, since we don't receive beforepaste event, but receive
       // beforecut and beforecopy events.
       case 'paste':
-        return this.isRenamingInProgress()
-                   ? this.document_.queryCommandEnabled(commandId)
-                   : (!!this.fileTransferController_ &&
-                      this.fileTransferController_.queryPasteCommandEnabled());
+        return this.isRenamingInProgress() ?
+                   this.document_.queryCommandEnabled(commandId) :
+                   (!!this.fileTransferController_ &&
+                    this.fileTransferController_.queryPasteCommandEnabled());
 
       case 'rename':
         return (// Initialized to the point where we have a current directory
@@ -1089,11 +1086,11 @@ FileManager.prototype = {
                 this.selection.totalCount == 1);
 
       case 'delete':
-        return (this.isRenamingInProgress()
-                ? this.document_.queryCommandEnabled(commandId)
-                : !readonly &&
-                  this.selection &&
-                  this.selection.totalCount > 0);
+        return (this.isRenamingInProgress() ?
+                this.document_.queryCommandEnabled(commandId) :
+                !readonly &&
+                    this.selection &&
+                    this.selection.totalCount > 0);
 
       case 'newfolder':
         return !readonly &&
@@ -1484,8 +1481,10 @@ FileManager.prototype = {
       return;
 
     if (!path) {
-      this.directoryModel_.setupDefaultPath();
-      return;
+      path = this.directoryModel_.getDefaultDirectory();
+    } else if (path.indexOf('/') == -1) {
+      // Path is a file name.
+      path = this.directoryModel_.getDefaultDirectory() + '/' + path;
     }
 
     // In the FULL_PAGE mode if the hash path points to a file we might have