Bug 432427: update 'download history' checkbox state to correctly reflect dependency on 'browsing history' checkbox, r=dietrich, a=beltzner

browser/base/content/sanitize.xul

@@ -114,15 +114,34 @@
           return undefined;
         },
 
+        onReadDownloads: function (aEvent)
+        {
+          // Call the common function that will update the accept button if needed
+          this.onReadGeneric();
+
+          let historyPref = document.getElementById("privacy.item.history")
+          let downloadPref = document.getElementById("privacy.item.downloads");
+
+          // Disable the checkbox if history is selected
+          let downloads = document.getElementById("downloads-checkbox");
+          downloads.disabled = historyPref.value;
+
+          // The "Download History" checkbox is selected if either of the history or
+          // downloads preferences are true.
+          return historyPref.value || downloadPref.value;
+        },
+
         updateDownloadHistory: function ()
         {
           // When toggling history, we automatically clear download history too,
-          // so we disable that control.
+          // so we disable that control and set its value to true.
           let downloads = document.getElementById("downloads-checkbox");
           let history = document.getElementById("history-checkbox");
           let s = new Sanitizer();
           downloads.disabled = history.checked ||
                                !s.canClearItem("downloads");
+          if (history.checked)
+            downloads.checked = true;
         },
       };
     ]]>
@@ -152,7 +171,7 @@
               label="&itemDownloads.label;"
               accesskey="&itemDownloads.accesskey;"
               preference="privacy.item.downloads"
-              onsyncfrompreference="return gSanitizePromptDialog.onReadGeneric();"/>
+              onsyncfrompreference="return gSanitizePromptDialog.onReadDownloads();"/>
     <checkbox label="&itemFormSearchHistory.label;"
               accesskey="&itemFormSearchHistory.accesskey;"
               preference="privacy.item.formdata"