Fix comment prefix stripping

examples/book/src/SUMMARY.md

@@ -3,4 +3,4 @@
 [Lib](lib.rs)
 
 - [Chapter 1](./chapter1.rs)
-  - [Chapter 1 - 1](./chapter1/chapter1_1.rs)
+  - [Chapter 1 - 1](./chapter1/chapter1_1.md)

examples/book/src/chapter1.rs

@@ -1,5 +1,3 @@
-pub mod chapter1_1;
-
 pub fn body() {
     // Test
     // Test

examples/book/src/chapter1/chapter1_1.md

@@ -0,0 +1,6 @@
+# Chapter 1.1
+
+- List 1
+- List 2
+
+Test

examples/book/src/lib.rs

@@ -4,14 +4,22 @@ pub fn body() {
     // xyzabc
     let _w = 0;
 
+    /*
+    x
+    - List 0
+    - List 1
+      - List 1 1
+      - List 1 2
+    */
     // Test
     let x = 1;
     // Test2
     //
     // - List 0
-    // - List 1
+    //- List 1
     //   - List 1 1
     //   - List 1 2
+    //
     //Test4
     let y = 1;
 

packages/mdbook-rust/src/main.rs

@@ -182,10 +182,21 @@ fn write_comment(comment: ast::Comment, prefix: &str) -> String {
     let comment_text = match comment.kind().shape {
         ast::CommentShape::Line => comment_suffix,
         ast::CommentShape::Block => comment_suffix.strip_suffix("*/").unwrap_or(comment_suffix),
+    };
+
+    let mut lines = comment_text.split('\n');
+    let mut output = String::new();
+
+    if let Some(first_line) = lines.next() {
+        output.push_str(first_line.strip_prefix(' ').unwrap_or(first_line));
     }
-    .trim_start();
 
-    write_lines(comment_text, prefix)
+    for line in lines {
+        output.push('\n');
+        output.push_str(line.strip_prefix(prefix).unwrap_or(line))
+    }
+
+    output
 }
 
 fn parse_module(source_text: &str) -> Result<SourceFile> {
@@ -267,3 +278,5 @@ fn expect_kind(
         bail!("Unexpected token")
     }
 }
+
+// TODO: Tests