Fix panic on blockquote

src/comment.rs

@@ -462,9 +462,9 @@ impl ItemizedBlock {
     fn get_marker_length(trimmed: &str) -> Option<usize> {
         // https://spec.commonmark.org/0.30/#bullet-list-marker or
         // https://spec.commonmark.org/0.30/#block-quote-marker
-        let itemized_start = ["* ", "- ", "> ", "+ "];
-        if itemized_start.iter().any(|s| trimmed.starts_with(s)) {
-            return Some(2); // All items in `itemized_start` have length 2.
+        let itemized_start = ["* ", "- ", ">", "+ "];
+        if let Some(s) = itemized_start.iter().find(|&&s| trimmed.starts_with(s)) {
+            return Some(s.len());
         }
 
         // https://spec.commonmark.org/0.30/#ordered-list-marker, where at most 2 digits are
@@ -492,13 +492,14 @@ impl ItemizedBlock {
 
         // Markdown blockquote start with a "> "
         if line.trim_start().starts_with('>') {
-            // remove the original +2 indent because there might be multiple nested block quotes
+            // remove the original +1 indent because there might be multiple nested block quotes
             // and it's easier to reason about the final indent by just taking the length
             // of the new line_start. We update the indent because it effects the max width
             // of each formatted line.
-            line_start = itemized_block_quote_start(line, line_start, 2);
+            line_start = itemized_block_quote_start(line, line_start, 1);
             indent = line_start.len();
         }
+
         Some(ItemizedBlock {
             lines: vec![line[indent..].to_string()],
             indent,
@@ -551,18 +552,26 @@ impl ItemizedBlock {
 /// The original line_start likely contains indentation (whitespaces), which we'd like to
 /// replace with '> ' characters.
 fn itemized_block_quote_start(line: &str, mut line_start: String, remove_indent: usize) -> String {
-    let quote_level = line
-        .chars()
-        .take_while(|c| !c.is_alphanumeric())
-        .fold(0, |acc, c| if c == '>' { acc + 1 } else { acc });
+    let mut quote_level = 0;
+    let mut chars = line.trim_start().chars().peekable();
+
+    while chars.peek() == Some(&'>') {
+        chars.next();
+        quote_level += 1;
+        // Skip all spaces after '>'
+        while chars.peek() == Some(&' ') {
+            chars.next();
+        }
+    }
 
     for _ in 0..remove_indent {
         line_start.pop();
     }
 
     for _ in 0..quote_level {
-        line_start.push_str("> ")
+        line_start.push_str("> ");
     }
+
     line_start
 }
 

tests/source/itemized-blocks/no_wrap.rs

@@ -79,3 +79,12 @@ fn func2() {}
 ///  * `tag` is a tag that identifies the message type
 ///  * `msg` is the (serialized) message
 fn func3() {}
+
+/// >>This is a blockquote comment that is very long and should be wrapped according to max_width setting
+/// >> This is a blockquote comment that is very long and should be wrapped according to max_width setting
+/// >   >This is a blockquote comment that is very long and should be wrapped according to max_width setting
+/// >   > This is a blockquote comment that is very long and should be wrapped according to max_width setting
+/// >   >    This is a blockquote comment that is very long and should be wrapped according to max_width setting
+/// > >= >> >>= >>> >>>= This is a blockquote comment that is very long and should be wrapped according to max_width setting
+/// > > = >> >>= >>> >>>= This is a blockquote comment that is very long and should be wrapped according to max_width setting
+fn func4() {}

tests/source/itemized-blocks/wrap.rs

@@ -87,3 +87,12 @@ fn func2() {}
 ///  * `tag` is a tag that identifies the message type
 ///  * `msg` is the (serialized) message
 fn func3() {}
+
+/// >>This is a blockquote comment that is very long and should be wrapped according to max_width setting
+/// >> This is a blockquote comment that is very long and should be wrapped according to max_width setting
+/// >   >This is a blockquote comment that is very long and should be wrapped according to max_width setting
+/// >   > This is a blockquote comment that is very long and should be wrapped according to max_width setting
+/// >   >    This is a blockquote comment that is very long and should be wrapped according to max_width setting
+/// > >= >> >>= >>> >>>= This is a blockquote comment that is very long and should be wrapped according to max_width setting
+/// > > = >> >>= >>> >>>= This is a blockquote comment that is very long and should be wrapped according to max_width setting
+fn func4() {}

tests/target/itemized-blocks/no_wrap.rs

@@ -79,3 +79,12 @@ fn func2() {}
 ///  * `tag` is a tag that identifies the message type
 ///  * `msg` is the (serialized) message
 fn func3() {}
+
+/// >>This is a blockquote comment that is very long and should be wrapped according to max_width setting
+/// >> This is a blockquote comment that is very long and should be wrapped according to max_width setting
+/// >   >This is a blockquote comment that is very long and should be wrapped according to max_width setting
+/// >   > This is a blockquote comment that is very long and should be wrapped according to max_width setting
+/// >   >    This is a blockquote comment that is very long and should be wrapped according to max_width setting
+/// > >= >> >>= >>> >>>= This is a blockquote comment that is very long and should be wrapped according to max_width setting
+/// > > = >> >>= >>> >>>= This is a blockquote comment that is very long and should be wrapped according to max_width setting
+fn func4() {}

tests/target/itemized-blocks/wrap.rs

@@ -147,3 +147,26 @@ fn func2() {}
 ///    type
 ///  * `msg` is the (serialized) message
 fn func3() {}
+
+/// >>This is a blockquote comment that is very
+/// > > long and should be wrapped according to
+/// > > max_width setting
+/// >> This is a blockquote comment that is very
+/// > > long and should be wrapped according to
+/// > > max_width setting
+/// >   >This is a blockquote comment that is very
+/// > > long and should be wrapped according to
+/// > > max_width setting
+/// >   > This is a blockquote comment that is
+/// > > very long and should be wrapped according
+/// > > to max_width setting
+/// >   >    This is a blockquote comment that is
+/// > > very long and should be wrapped according
+/// > > to max_width setting
+/// > >=>> >>= >>> >>>= This is a blockquote
+/// > > comment that is very long and should be
+/// > > wrapped according to max_width setting
+/// > > = >> >>= >>> >>>= This is a blockquote
+/// > > comment that is very long and should be
+/// > > wrapped according to max_width setting
+fn func4() {}