Merge pull request #2155 from topecongiro/issue-1603

Prevent panicking by a nested comment

Author: nrc

src/lists.rs

@@ -572,10 +572,12 @@ where
             let comment_end = match self.inner.peek() {
                 Some(..) => {
                     let mut block_open_index = post_snippet.find("/*");
-                    // check if it really is a block comment (and not //*)
+                    // check if it really is a block comment (and not `//*` or a nested comment)
                     if let Some(i) = block_open_index {
-                        if i > 0 && &post_snippet[i - 1..i] == "/" {
-                            block_open_index = None;
+                        match post_snippet.find("/") {
+                            Some(j) if j < i => block_open_index = None,
+                            _ if i > 0 && &post_snippet[i - 1..i] == "/" => block_open_index = None,
+                            _ => (),
                         }
                     }
                     let newline_index = post_snippet.find('\n');

tests/source/comment.rs

@@ -81,3 +81,10 @@ fn some_fn4()
 /* some comment some comment some comment some comment some comment some comment some comment */
 {
 }
+
+// #1603
+pub enum Foo {
+    A, // `/** **/`
+    B, // `/*!`
+    C,
+}

tests/target/comment.rs

@@ -86,3 +86,10 @@ fn some_fn4()
 // some comment
 {
 }
+
+// #1603
+pub enum Foo {
+    A, // `/** **/`
+    B, // `/*!`
+    C,
+}