From 712286337e3d9fbbeb84d8d8a283f95577706302 Mon Sep 17 00:00:00 2001
From: FUTATSUKI Yasuhito <futatuki@yf.bsdclub.org>
Date: Sat, 26 Aug 2023 23:47:26 +0900
Subject: [PATCH 1/2] Implement diff compatible -L (--label) option.

With this, we can use difft as a external diff for Apache Subversion,
in the form:

    svn diff --diff-cmd=difft -x '<at least one difft option>'
---
 src/options.rs | 29 ++++++++++++++++++++++++++++-
 1 file changed, 28 insertions(+), 1 deletion(-)

diff --git a/src/options.rs b/src/options.rs
index 0321c23f45..1f833a4ff5 100644
--- a/src/options.rs
+++ b/src/options.rs
@@ -140,6 +140,15 @@ fn app() -> clap::Command<'static> {
                 .validator(|s| s.parse::<u32>())
                 .required(false),
         )
+        .arg(
+            Arg::new("label").short('L')
+                .long("label")
+                .takes_value(true)
+                .value_name("LABEL")
+                .max_occurrences(2)
+                .allow_invalid_utf8(true)
+                .help("Label of file(s) which should be used for printing instead of PATH(s).")
+        )
         .arg(
             Arg::new("width")
                 .long("width")
@@ -740,7 +749,25 @@ pub(crate) fn parse_args() -> Mode {
         [lhs_path, rhs_path] => {
             let lhs_arg = FileArgument::from_cli_argument(lhs_path);
             let rhs_arg = FileArgument::from_cli_argument(rhs_path);
-            let display_path = build_display_path(&lhs_arg, &rhs_arg);
+            let display_path = if matches.is_present("label") {
+                let labels: Vec<_> = matches.values_of_os("label").unwrap_or_default().collect();
+                let (_lhs_display_path, rhs_display_path) = match &labels[..] {
+                    [lhs_display_path, rhs_display_path] => (
+                        lhs_display_path.to_string_lossy().to_string(),
+                        rhs_display_path.to_string_lossy().to_string(),
+                    ),
+                    [display_path] => (
+                        display_path.to_string_lossy().to_string(),
+                        display_path.to_string_lossy().to_string(),
+                    ),
+                    _ => {
+                        unreachable!("clap has already validated label")
+                    }
+                };
+                rhs_display_path
+            } else {
+                build_display_path(&lhs_arg, &rhs_arg)
+            };
 
             let lhs_permissions = lhs_arg.permissions();
             let rhs_permissions = rhs_arg.permissions();

From ff7cbca9ab6e747b825b8928f4610e1fad619268 Mon Sep 17 00:00:00 2001
From: FUTATSUKI Yasuhito <futatuki@yf.bsdclub.org>
Date: Sun, 27 Aug 2023 00:02:36 +0900
Subject: [PATCH 2/2] Implement -u option with no effect

If "svn diff --diff-cmd" is called without -x option, svn executes
external diff command with -u option. So this allows to use
difft as external diff for Apache Subversion, without extra options.
---
 src/options.rs | 7 +++++++
 1 file changed, 7 insertions(+)

diff --git a/src/options.rs b/src/options.rs
index 1f833a4ff5..6d4f25da48 100644
--- a/src/options.rs
+++ b/src/options.rs
@@ -140,6 +140,13 @@ fn app() -> clap::Command<'static> {
                 .validator(|s| s.parse::<u32>())
                 .required(false),
         )
+        .arg(
+            // Dummy 'unified' flag of POSIX/GNU diff utility for svn support:
+            // This takes no effect.
+            Arg::new("nop_unified")
+                .short('u')
+                .hide(true)
+        )
         .arg(
             Arg::new("label").short('L')
                 .long("label")