Merge pull request rust-lang#3172 from scampi/issue3153

trim the start of a line when wrapping an item in preparation for formatting

Author: nrc

src/comment.rs

@@ -398,7 +398,7 @@ impl CodeBlockAttribute {
 /// Block that is formatted as an item.
 ///
 /// An item starts with either a star `*` or a dash `-`. Different level of indentation are
-/// handled.
+/// handled by shrinking the shape accordingly.
 struct ItemizedBlock {
     /// the number of whitespaces up to the item sigil
     indent: usize,
@@ -585,7 +585,7 @@ impl<'a> CommentRewrite<'a> {
 
         if let Some(ref ib) = self.item_block {
             if ib.in_block(&line) {
-                self.item_block_buffer.push_str(&line);
+                self.item_block_buffer.push_str(line.trim_start());
                 self.item_block_buffer.push('\n');
                 return false;
             }

tests/source/issue-3153.rs

@@ -0,0 +1,9 @@
+// rustfmt-wrap_comments: true
+
+/// This may panic if:
+/// - there are fewer than `max_header_bytes` bytes preceding the body
+/// - there are fewer than `max_footer_bytes` bytes following the body
+/// - the sum of the body bytes and post-body bytes is less than the sum
+///   of `min_body_and_padding_bytes` and `max_footer_bytes` (in other
+///   words, the minimum body and padding byte requirement is not met)
+fn foo() {}

tests/target/issue-3153.rs

@@ -0,0 +1,9 @@
+// rustfmt-wrap_comments: true
+
+/// This may panic if:
+/// - there are fewer than `max_header_bytes` bytes preceding the body
+/// - there are fewer than `max_footer_bytes` bytes following the body
+/// - the sum of the body bytes and post-body bytes is less than the sum of
+///   `min_body_and_padding_bytes` and `max_footer_bytes` (in other words, the
+///   minimum body and padding byte requirement is not met)
+fn foo() {}