From 64959d606966e5d33a8b98f62d57774e4749de18 Mon Sep 17 00:00:00 2001
From: Austen Adler <agadler@austenadler.com>
Date: Thu, 6 Oct 2022 21:09:13 -0400
Subject: [PATCH] Fix empty registers

---
 kakplugin/src/errors.rs | 7 +++++++
 kakplugin/src/lib.rs    | 9 ++++++++-
 2 files changed, 15 insertions(+), 1 deletion(-)

diff --git a/kakplugin/src/errors.rs b/kakplugin/src/errors.rs
index 3d31abc..1b9dca2 100644
--- a/kakplugin/src/errors.rs
+++ b/kakplugin/src/errors.rs
@@ -1,3 +1,4 @@
+use crate::Register;
 use std::{fmt, fmt::Display, num::ParseIntError};
 
 #[derive(Debug)]
@@ -22,6 +23,8 @@ pub enum KakError {
     CustomStatic(&'static str),
     /// The selections/selections_desc list passed was empty
     SetEmptySelections,
+    /// The register register has no content
+    EmptyRegister(Register),
 }
 
 impl std::error::Error for KakError {}
@@ -41,6 +44,9 @@ impl KakError {
             Self::SetEmptySelections => {
                 String::from("Attempted to set selections/selections_desc to empty list")
             }
+            Self::EmptyRegister(r) => {
+                format!("Empty register: {r}")
+            }
         }
     }
 }
@@ -62,6 +68,7 @@ impl Display for KakError {
                 f,
                 "Attempted to set selections/selections_desc to empty list"
             ),
+            Self::EmptyRegister(r) => write!(f, "Register {r} has no content"),
         }
     }
 }
diff --git a/kakplugin/src/lib.rs b/kakplugin/src/lib.rs
index 1c52f1b..872bdb0 100644
--- a/kakplugin/src/lib.rs
+++ b/kakplugin/src/lib.rs
@@ -354,5 +354,12 @@ where
 }
 
 pub fn reg(register: Register, keys: Option<&'_ str>) -> Result<Vec<String>, KakError> {
-    response(format!("%reg{{{}}}", register.kak_expanded()), keys)
+    let ret = response(format!("%reg{{{}}}", register.kak_expanded()), keys)?;
+
+    // Kak returns a single empty line
+    if &ret[..] == [""] {
+        return Err(KakError::EmptyRegister(register));
+    }
+
+    Ok(ret)
 }