fix: index out of bound on empty comment

csmoe · web-flow · commit 5dd16844094f · 2022-04-19T05:48:15.000Z
diff --git a/compiler/rustc_ast/src/util/comments.rs b/compiler/rustc_ast/src/util/comments.rs
@@ -44,6 +44,10 @@ pub fn beautify_doc_string(data: Symbol, kind: CommentKind) -> Symbol {
     }
 
     fn get_horizontal_trim<'a>(lines: &'a [&str], kind: CommentKind) -> Option<String> {
+        if lines.is_empty() {
+            return None;
+        }
+
         let mut i = usize::MAX;
         let mut first = true;
 

Original file line number	Diff line number	Diff line change
`@@ -44,6 +44,10 @@ pub fn beautify_doc_string(data: Symbol, kind: CommentKind) -> Symbol {`
`44`	`44`	`}`
`45`	`45`
`46`	`46`	`fn get_horizontal_trim<'a>(lines: &'a [&str], kind: CommentKind) -> Option<String> {`
	`47`	`+ if lines.is_empty() {`
	`48`	`+ return None;`
	`49`	`+ }`
	`50`	`+`
`47`	`51`	`let mut i = usize::MAX;`
`48`	`52`	`let mut first = true;`
`49`	`53`