auto merge of #4133 : mttr/servo/form_resetting, r=jdm

We can reset `<input type=text>` fields! I wish I could've done something with checkboxes, but unfortunately, that's it for now.

In addition to that, this PR implements `HTMLInputAttribute.defaultValue`, updates wpt-test to expect passing tests as a result of that implementation, and fixes an index error crash with text inputs.

edit: also includes an html example where one may lazily watch form resets in action: ` tests/html/form_reset_handsfree.html`

1 files changed, 7 insertions, 1 deletions

diff --git a/components/script/textinput.rs b/components/script/textinput.rs
index d39d22918c0..ed120aae943 100644
--- a/components/script/textinput.rs
+++ b/components/script/textinput.rs
@@ -295,6 +295,12 @@ impl TextInput {
             vec!(content)
         };
         self.edit_point.line = min(self.edit_point.line, self.lines.len() - 1);
-        self.edit_point.index = min(self.edit_point.index, self.current_line_length() - 1);
+
+        if self.current_line_length() == 0 {
+            self.edit_point.index = 0;
+        }
+        else {
+            self.edit_point.index = min(self.edit_point.index, self.current_line_length() - 1);
+        }
     }
 }