fix(engine): add workaround to markdown parsing to avoid crashing espanso with malformed markdown. Fix #759

espanso-engine/src/process/middleware/markdown.rs

@@ -17,6 +17,8 @@
  * along with espanso.  If not, see <https://www.gnu.org/licenses/>.
  */
 
+use log::error;
+
 use super::super::Middleware;
 use crate::event::{effect::HtmlInjectRequest, Event, EventType};
 
@@ -37,7 +39,12 @@ impl Middleware for MarkdownMiddleware {
   fn next(&self, event: Event, _: &mut dyn FnMut(Event)) -> Event {
     if let EventType::MarkdownInject(m_event) = &event.etype {
       // Render the markdown into HTML
-      let html = markdown::to_html(&m_event.markdown);
+      // NOTE: we wrap the `to_html` call between catch_unwind because if the markdown is malformed,
+      // the library panics. Ideally, the library would return a Result::Err in that case, but
+      // for now it doesn't, so we employ that workaround.
+      // See also: https://github.com/federico-terzi/espanso/issues/759
+      let html = std::panic::catch_unwind(|| markdown::to_html(&m_event.markdown));
+      if let Ok(html) = html {
         let mut html = html.trim();
 
         // Remove the surrounding paragraph
@@ -54,6 +61,11 @@ impl Middleware for MarkdownMiddleware {
             html: html.to_owned(),
           }),
         );
+      } else {
+        error!("unable to convert markdown to HTML, is it malformed?");
+
+        return Event::caused_by(event.source_id, EventType::NOOP);
+      }
     }
 
     event