From 4e3e5a879d4ff03ae09efb2f9ffe44ca823ed2ae Mon Sep 17 00:00:00 2001
From: Brian Anderson <banderson@mozilla.com>
Date: Sat, 15 Sep 2012 16:31:38 -0700
Subject: [PATCH] Do a little less copying in TextRun.split

---
 src/rust-mozjs             |  2 +-
 src/servo/text/text_run.rs | 18 ++++++++++++------
 2 files changed, 13 insertions(+), 7 deletions(-)

diff --git a/src/rust-mozjs b/src/rust-mozjs
index e2b17f323b0..de66662c301 160000
--- a/src/rust-mozjs
+++ b/src/rust-mozjs
@@ -1 +1 @@
-Subproject commit e2b17f323b0ab2d6a2d806d114bd1e61f3b1ba50
+Subproject commit de66662c301b2c00dacabdf0d82adf22d16232b4
diff --git a/src/servo/text/text_run.rs b/src/servo/text/text_run.rs
index 5333501fa7a..16c4e6a4e27 100644
--- a/src/servo/text/text_run.rs
+++ b/src/servo/text/text_run.rs
@@ -30,18 +30,18 @@ impl TextRun {
         let mut curr_run = ~"";
 
         for iter_indivisible_slices(font, self.text) |slice| {
-            let mut candidate = curr_run;
+            let mut candidate = copy curr_run;
 
             if candidate.is_not_empty() {
-                candidate += " "; // FIXME: just inserting spaces between words can't be right
+                str::push_str(candidate, " "); // FIXME: just inserting spaces between words can't be right
             }
 
-            candidate += slice;
+            str::push_str(candidate, slice);
 
             let glyphs = shape_text(font, candidate);
             let size = glyph_run_size(glyphs);
             if size.width <= h_offset {
-                curr_run = candidate;
+                curr_run = move candidate;
             } else {
                 break;
             }
@@ -50,8 +50,14 @@ impl TextRun {
         assert curr_run.is_not_empty();
 
         let first = move curr_run;
-        let second = str::slice(self.text, first.len(), self.text.len());
-        let second = second.trim_left();
+        let second_start = match str::find_from(self.text, first.len(), |c| !char::is_whitespace(c)) {
+            Some(idx) => idx,
+            None => {
+                // This will be an empty string
+                self.text.len()
+            }
+        };
+        let second = str::slice(self.text, second_start, self.text.len());
         return (TextRun(font, first), TextRun(font, second));
     }
 }