doc_lazy_continuation: Correctly count indent with backslashes

changelog: [`doc_lazy_continuation`]: correctly count indent with backslashes

Author: notriddle

clippy_lints/src/doc/mod.rs

@@ -871,7 +871,12 @@ fn check_doc<'a, Events: Iterator<Item = (pulldown_cmark::Event<'a>, Range<usize
                 }
                 if let Start(Item) = event {
                     if let Some((_next_event, next_range)) = events.peek() {
-                        containers.push(Container::List(next_range.start - range.start));
+                        let mut start = next_range.start;
+                        if start > 0 && doc.as_bytes().get(start - 1) == Some(&b'\\') {
+                            // backslashes aren't in the event stream...
+                            start -= 1;
+                        }
+                        containers.push(Container::List(start - range.start));
                     } else {
                         containers.push(Container::List(0));
                     }

tests/ui/doc/doc_lazy_list.fixed

@@ -75,3 +75,9 @@ fn seven() {}
 ///   ]
 //~^ ERROR: doc list item without indentation
 fn eight() {}
+
+#[rustfmt::skip]
+// https://github.com/rust-lang/rust-clippy/issues/13705
+/// - \[text in square brackets\] with a long following description
+///   that goes over multiple lines
+pub fn backslash_escaped_square_braces() {}

tests/ui/doc/doc_lazy_list.rs

@@ -75,3 +75,9 @@ fn seven() {}
 ///  ]
 //~^ ERROR: doc list item without indentation
 fn eight() {}
+
+#[rustfmt::skip]
+// https://github.com/rust-lang/rust-clippy/issues/13705
+/// - \[text in square brackets\] with a long following description
+///   that goes over multiple lines
+pub fn backslash_escaped_square_braces() {}