LaTeX: a "[" after a line break or at the start of a list item stays text (#1099)

* Contributors: add Jason Brashear to people.toml

* LaTeX: a "[" after a line break or at the start of a list item stays text

contributors/people.toml

@@ -72,3 +72,7 @@ sync_github_name = false
 real_name = "Manuel Carmona"
 display_name = "manucarcor"
 [people.odedigo]
+
+[people.webdevtodayjason]
+display_name = "Jason Brashear"
+sync_github_name = false

crates/formats/src/latex.rs

@@ -416,6 +416,8 @@ pub fn escape_text(s: &str) -> String {
             '>' => o.push_str("\\textgreater{}"),
             '|' => o.push_str("\\textbar{}"),
             '\u{A0}' => o.push('~'),
+            // An opening bracket here would become an optional item or line-break argument.
+            '[' if !line_has_text => o.push_str("{[}"),
             // Keep TeX from joining `--`, ``` `` ``` and `''` into dashes and quotes.
             '-' if prev == '-' => o.push_str("{}-"),
             '`' => o.push_str("\\textasciigrave{}"),
@@ -3029,6 +3031,15 @@ Caf\'e na\"ive \c{c}a \v{s}\'{e} and {\bfseries grouped bold} after.
         assert!(md.contains("π r^2"), "{md}");
     }
 
+    #[test]
+    fn leading_brackets_stay_text() {
+        // `\item [x]` and `\\ [1]` would read the bracket as an optional argument.
+        assert_eq!(escape_text("[x] a\n [1] b [c]"), "{[}x] a\\\\\n {[}1] b [c]");
+        let doc = crate::markdown::import("- [x] done");
+        let back = import(export(&doc).as_bytes());
+        assert_eq!(back.plain_text(Default::default()), "[x] done");
+    }
+
     #[test]
     fn special_characters_round_trip() {
         let text = "50% of $5 & #1_a {b} ~c^ \\d <e> |f| -- ``g'' tab\there";