Bug 1062387 - Part 1. Fix clearing of camera preferences. r=mikeh

dom/camera/CameraPreferences.cpp

@@ -45,6 +45,10 @@ CameraPreferences::UpdatePref(const char* aPref, nsresult& aVal)
   nsresult rv = Preferences::GetUint(aPref, &val);
   if (NS_SUCCEEDED(rv)) {
     aVal = static_cast<nsresult>(val);
+  } else if(rv == NS_ERROR_UNEXPECTED) {
+    // Preference does not exist
+    rv = NS_OK;
+    aVal = NS_OK;
   }
   return rv;
 }
@@ -57,6 +61,10 @@ CameraPreferences::UpdatePref(const char* aPref, uint32_t& aVal)
   nsresult rv = Preferences::GetUint(aPref, &val);
   if (NS_SUCCEEDED(rv)) {
     aVal = val;
+  } else if(rv == NS_ERROR_UNEXPECTED) {
+    // Preference does not exist
+    rv = NS_OK;
+    aVal = 0;
   }
   return rv;
 }
@@ -69,6 +77,10 @@ CameraPreferences::UpdatePref(const char* aPref, nsACString& aVal)
   nsresult rv = Preferences::GetCString(aPref, &val);
   if (NS_SUCCEEDED(rv)) {
     aVal = val;
+  } else if(rv == NS_ERROR_UNEXPECTED) {
+    // Preference does not exist
+    rv = NS_OK;
+    aVal.Truncate();
   }
   return rv;
 }
@@ -81,6 +93,10 @@ CameraPreferences::UpdatePref(const char* aPref, bool& aVal)
   nsresult rv = Preferences::GetBool(aPref, &val);
   if (NS_SUCCEEDED(rv)) {
     aVal = val;
+  } else if(rv == NS_ERROR_UNEXPECTED) {
+    // Preference does not exist
+    rv = NS_OK;
+    aVal = false;
   }
   return rv;
 }