ICE

This commit will cause rustc to ICE.

Author: topecongiro

src/reorder.rs

@@ -22,7 +22,7 @@ use syntax::{ast, attr, codemap::Span};
 use attr::filter_inline_attrs;
 use codemap::LineRangeUtils;
 use comment::combine_strs_with_missing_comments;
-use imports::UseTree;
+use imports::{merge_use_trees, UseTree};
 use items::{is_mod_decl, rewrite_extern_crate, rewrite_mod};
 use lists::{itemize_list, write_list, ListFormatting, ListItem};
 use rewrite::{Rewrite, RewriteContext};
@@ -121,12 +121,13 @@ fn rewrite_reorderable_items(
                 .iter()
                 .filter_map(|item| UseTree::from_ast_with_normalization(context, item))
                 .collect();
+            let merged_items = merge_use_trees(normalized_items);
 
             // 4 = "use ", 1 = ";"
             let nested_shape = shape.offset_left(4)?.sub_width(1)?;
             let list_items = itemize_list(
                 context.snippet_provider,
-                normalized_items.iter(),
+                merged_items.iter(),
                 "",
                 ";",
                 |item| item.span.lo(),
@@ -137,7 +138,7 @@ fn rewrite_reorderable_items(
                 false,
             );
 
-            let mut item_pair_vec: Vec<_> = list_items.zip(&normalized_items).collect();
+            let mut item_pair_vec: Vec<_> = list_items.zip(&merged_items).collect();
             item_pair_vec.sort_by(|a, b| a.1.cmp(b.1));
             let item_vec: Vec<_> = item_pair_vec.into_iter().map(|pair| pair.0).collect();