diff --git a/gfx/cairo/cairo/src/cairo-hash.c b/gfx/cairo/cairo/src/cairo-hash.c
--- a/gfx/cairo/cairo/src/cairo-hash.c
+++ b/gfx/cairo/cairo/src/cairo-hash.c
@@ -443,18 +466,18 @@ _cairo_hash_table_random_entry (cairo_ha
 
 /**
  * _cairo_hash_table_insert:
  * @hash_table: a hash table
  * @key_and_value: an entry to be inserted
  *
  * Insert the entry #key_and_value into the hash table.
  *
- * WARNING: It is a fatal error if an entry exists in the hash table
- * with a matching key, (this function will halt).
+ * WARNING: There must not be an existing entry in the hash table
+ * with a matching key.
  *
  * WARNING: It is a fatal error to insert an element while
  * an iterator is running
  *
  * Instead of using insert to replace an entry, consider just editing
  * the entry obtained with _cairo_hash_table_lookup. Or if absolutely
  * necessary, use _cairo_hash_table_remove first.
  *
@@ -467,23 +490,20 @@ _cairo_hash_table_insert (cairo_hash_tab
 {
     cairo_status_t status;
     cairo_hash_entry_t **entry;
 
     /* Insert is illegal while an iterator is running. */
     assert (hash_table->iterating == 0);
 
     entry = _cairo_hash_table_lookup_internal (hash_table,
-					       key_and_value, FALSE);
+					       key_and_value, TRUE);
-
-    if (ENTRY_IS_LIVE(*entry))
-    {
-	/* User is being bad, let's crash. */
-	ASSERT_NOT_REACHED;
-    }
+    /* _cairo_hash_table_lookup_internal with key_unique = TRUE
+     * aways returns an available entry. */
+    assert (! ENTRY_IS_LIVE(*entry));
 
     *entry = key_and_value;
     hash_table->live_entries++;
 
     status = _cairo_hash_table_resize (hash_table);
     if (status) {
 	/* abort the insert... */
 	*entry = DEAD_ENTRY;