Fix expected-indentation errors with end-of-line comments (#4438)

crates/ruff/resources/test/fixtures/pycodestyle/E11.py

@@ -40,3 +40,12 @@ def start():
 #: E117 W191
 def start():
 		print()
+#: E112
+if False:  #
+print()
+#:
+if False:
+    print()
+#:
+if False:  #
+    print()

crates/ruff/src/rules/pycodestyle/rules/logical_lines/mod.rs

@@ -89,7 +89,8 @@ impl<'a> LogicalLines<'a> {
         let mut builder = LogicalLinesBuilder::with_capacity(tokens.len());
         let mut parens: u32 = 0;
 
-        for (token, range) in tokens.iter().flatten() {
+        let mut iter = tokens.iter().flatten().peekable();
+        while let Some((token, range)) = iter.next() {
             let token_kind = TokenKind::from_token(token);
             builder.push_token(token_kind, *range);
 
@@ -100,9 +101,25 @@ impl<'a> LogicalLines<'a> {
                 TokenKind::Rbrace | TokenKind::Rpar | TokenKind::Rsqb => {
                     parens -= 1;
                 }
-                TokenKind::Newline | TokenKind::NonLogicalNewline | TokenKind::Comment
-                    if parens == 0 =>
-                {
+                TokenKind::Comment if parens == 0 => {
+                    // If a comment is followed by a newline, ignore it, and we'll build the line
+                    // when we process the newline. Otherwise, we'll end up creating one logical
+                    // line here, and then another, empty logical line when we process the newline.
+                    //
+                    // The lexer will always emit a newline after a comment _unless_ the comment
+                    // appears at the start of a logical line.
+                    if let Some((token, ..)) = iter.peek() {
+                        let token_kind = TokenKind::from_token(token);
+                        if matches!(
+                            token_kind,
+                            TokenKind::Newline | TokenKind::NonLogicalNewline
+                        ) {
+                            continue;
+                        }
+                    }
+                    builder.finish_line();
+                }
+                TokenKind::Newline | TokenKind::NonLogicalNewline if parens == 0 => {
                     builder.finish_line();
                 }
                 _ => {}

crates/ruff/src/rules/pycodestyle/snapshots/ruff__rules__pycodestyle__tests__E112_E11.py.snap

@@ -11,4 +11,14 @@ E11.py:9:1: E112 Expected an indented block
 13 | print()
    |
 
+E11.py:45:1: E112 Expected an indented block
+   |
+45 | #: E112
+46 | if False:  #
+47 | print()
+   |  E112
+48 | #:
+49 | if False:
+   |
+
 

crates/ruff/src/rules/pycodestyle/snapshots/ruff__rules__pycodestyle__tests__E117_E11.py.snap

@@ -27,6 +27,8 @@ E11.py:42:1: E117 Over-indented
 43 | def start():
 44 |         print()
    | ^^^^^^^^ E117
+45 | #: E112
+46 | if False:  #
    |