From a14906f52fd2c6bd06384b1b22a30e02fabeaa00 Mon Sep 17 00:00:00 2001
From: Peter Ammon <rf@fishshell.com>
Date: Fri, 27 Dec 2024 15:00:41 -0800
Subject: [PATCH] Fix a todo!

Stop cloning the delimiter unnecessarily in builtin read.
---
 src/builtins/read.rs | 26 +++++++++++++-------------
 1 file changed, 13 insertions(+), 13 deletions(-)

diff --git a/src/builtins/read.rs b/src/builtins/read.rs
index 7051897f3..d57e153b0 100644
--- a/src/builtins/read.rs
+++ b/src/builtins/read.rs
@@ -686,15 +686,15 @@ pub fn read(parser: &Parser, streams: &mut IoStreams, argv: &mut [&wstr]) -> Opt
             continue;
         }
 
-        // todo!("don't clone")
-        let delimiter = opts
-            .delimiter
-            .clone()
-            .or_else(|| {
-                let ifs = parser.vars().get_unless_empty(L!("IFS"));
-                ifs.map(|ifs| ifs.as_string())
-            })
-            .unwrap_or_default();
+        let mut ifs_delimiter = WString::new();
+        let delimiter: &wstr = opts.delimiter.as_deref().unwrap_or_else(|| {
+            ifs_delimiter = parser
+                .vars()
+                .get_unless_empty(L!("IFS"))
+                .map(|var| var.as_string())
+                .unwrap_or_default();
+            &ifs_delimiter
+        });
 
         if delimiter.is_empty() {
             // Every character is a separate token with one wrinkle involving non-array mode where
@@ -735,7 +735,7 @@ pub fn read(parser: &Parser, streams: &mut IoStreams, argv: &mut [&wstr]) -> Opt
             if opts.delimiter.is_none() {
                 // We're using IFS, so tokenize the buffer using each IFS char. This is for backward
                 // compatibility with old versions of fish.
-                let tokens = split_string_tok(&buff, &delimiter, None)
+                let tokens = split_string_tok(&buff, delimiter, None)
                     .into_iter()
                     .map(|s| s.to_owned())
                     .collect();
@@ -743,7 +743,7 @@ pub fn read(parser: &Parser, streams: &mut IoStreams, argv: &mut [&wstr]) -> Opt
                 var_ptr += 1;
             } else {
                 // We're using a delimiter provided by the user so use the `string split` behavior.
-                let splits = split_about(&buff, &delimiter, usize::MAX, false)
+                let splits = split_about(&buff, delimiter, usize::MAX, false)
                     .into_iter()
                     .map(|s| s.to_owned())
                     .collect();
@@ -757,7 +757,7 @@ pub fn read(parser: &Parser, streams: &mut IoStreams, argv: &mut [&wstr]) -> Opt
                 // compatibility with old versions of fish.
                 // Note the final variable gets any remaining text.
                 let mut var_vals: Vec<WString> =
-                    split_string_tok(&buff, &delimiter, Some(vars_left(var_ptr)))
+                    split_string_tok(&buff, delimiter, Some(vars_left(var_ptr)))
                         .into_iter()
                         .map(|s| s.to_owned())
                         .collect();
@@ -775,7 +775,7 @@ pub fn read(parser: &Parser, streams: &mut IoStreams, argv: &mut [&wstr]) -> Opt
                 // We're using a delimiter provided by the user so use the `string split` behavior.
                 // We're making at most argc - 1 splits so the last variable
                 // is set to the remaining string.
-                let splits = split_about(&buff, &delimiter, argc - 1, false);
+                let splits = split_about(&buff, delimiter, argc - 1, false);
                 assert!(splits.len() <= vars_left(var_ptr));
                 for split in splits {
                     parser.set_var_and_fire(argv[var_ptr], opts.place, vec![split.to_owned()]);