Add support for application in plain links.

src/compare/diff.rs

@@ -2973,8 +2973,8 @@ fn compare_plain_link<'b, 's>(
         ),
         (
             EmacsField::Required(":application"),
-            compare_identity,
-            compare_property_always_nil
+            |r| r.application,
+            compare_property_quoted_string
         ),
         (
             EmacsField::Required(":search-option"),

src/parser/plain_link.rs

@@ -8,10 +8,12 @@ use nom::character::complete::one_of;
 use nom::combinator::consumed;
 use nom::combinator::eof;
 use nom::combinator::map;
+use nom::combinator::map_parser;
 use nom::combinator::not;
 use nom::combinator::opt;
 use nom::combinator::peek;
 use nom::combinator::recognize;
+use nom::combinator::rest;
 use nom::combinator::verify;
 use nom::multi::many0;
 use nom::multi::many1;
@@ -56,6 +58,7 @@ pub(crate) fn plain_link<'b, 'g, 'r, 's>(
             path: path_plain.path,
             raw_link: path_plain.raw_link,
             search_option: path_plain.search_option,
+            application: path_plain.application,
         },
     ))
 }
@@ -66,6 +69,7 @@ struct PathPlain<'s> {
     path: &'s str,
     raw_link: &'s str,
     search_option: Option<&'s str>,
+    application: Option<&'s str>,
 }
 
 #[cfg_attr(feature = "tracing", tracing::instrument(ret, level = "debug"))]
@@ -107,6 +111,17 @@ fn parse_path_plain<'b, 'g, 'r, 's>(
     ))(input)
 }
 
+fn parse_file_and_application<'s>(
+    input: OrgSource<'s>,
+) -> Res<OrgSource<'s>, Option<OrgSource<'s>>> {
+    let (remaining, _) = tag("file")(input)?;
+    let (remaining, application) =
+        opt(map(tuple((tag("+"), rest)), |(_, application)| application))(remaining)?;
+    // Assert we consumed the entire protocol.
+    not(anychar)(remaining)?;
+    Ok((remaining, application))
+}
+
 fn file_path_plain<'b, 'g, 'r, 's>(
     context: RefContext<'b, 'g, 'r, 's>,
     input: OrgSource<'s>,
@@ -117,8 +132,12 @@ fn file_path_plain<'b, 'g, 'r, 's>(
         exit_matcher: &path_plain_end,
     });
     let parser_context = context.with_additional_node(&parser_context);
-    let (remaining, (raw_link, (_, path, search_option))) = consumed(tuple((
-        tag("file:"),
+    let (remaining, (raw_link, (application, _, path, search_option))) = consumed(tuple((
+        map_parser(
+            parser_with_context!(protocol)(&parser_context),
+            parse_file_and_application,
+        ),
+        tag(":"),
         parser_with_context!(path_plain)(&parser_context),
         opt(map(
             tuple((tag("::"), is_not(" \t\r\n"))),
@@ -132,6 +151,7 @@ fn file_path_plain<'b, 'g, 'r, 's>(
             path: path.into(),
             raw_link: raw_link.into(),
             search_option: search_option.map(Into::<&str>::into),
+            application: application.map(Into::<&str>::into),
         },
     ))
 }
@@ -158,6 +178,7 @@ fn protocol_path_plain<'b, 'g, 'r, 's>(
             path: path.into(),
             raw_link: raw_link.into(),
             search_option: None,
+            application: None,
         },
     ))
 }

src/types/object.rs

@@ -108,6 +108,7 @@ pub struct PlainLink<'s> {
     pub path: &'s str,
     pub raw_link: &'s str,
     pub search_option: Option<&'s str>,
+    pub application: Option<&'s str>,
 }
 
 #[derive(Debug, PartialEq)]