clippy: fix map_unwrap_or lint (#9678)

https://rust-lang.github.io/rust-clippy/master/index.html#map_unwrap_or

Cargo.toml

@@ -666,7 +666,6 @@ should_panic_without_expect = "allow"        # 2
 
 doc_markdown = "allow"
 unused_self = "allow"
-map_unwrap_or = "allow"
 enum_glob_use = "allow"
 ptr_cast_constness = "allow"
 borrow_as_ptr = "allow"

src/uu/cp/src/cp.rs

@@ -2319,8 +2319,7 @@ fn copy_file(
     let initial_dest_metadata = dest.symlink_metadata().ok();
     let dest_is_symlink = initial_dest_metadata
         .as_ref()
-        .map(|md| md.file_type().is_symlink())
-        .unwrap_or(false);
+        .is_some_and(|md| md.file_type().is_symlink());
     let dest_target_exists = dest.try_exists().unwrap_or(false);
     // Fail if dest is a dangling symlink or a symlink this program created previously
     if dest_is_symlink {

src/uu/fold/src/fold.rs

@@ -443,7 +443,7 @@ fn process_utf8_line<W: Write>(line: &str, ctx: &mut FoldContext<'_, W>) -> URes
             }
         }
 
-        let next_idx = iter.peek().map(|(idx, _)| *idx).unwrap_or(line_bytes.len());
+        let next_idx = iter.peek().map_or(line_bytes.len(), |(idx, _)| *idx);
 
         if ch == '\n' {
             *ctx.last_space = None;

src/uu/ls/src/ls.rs

@@ -479,8 +479,7 @@ fn extract_sort(options: &clap::ArgMatches) -> Sort {
     let sort_index = options
         .get_one::<String>(options::SORT)
         .and_then(|_| options.indices_of(options::SORT))
-        .map(|mut indices| indices.next_back().unwrap_or(0))
-        .unwrap_or(0);
+        .map_or(0, |mut indices| indices.next_back().unwrap_or(0));
     let time_index = get_last_index(options::sort::TIME);
     let size_index = get_last_index(options::sort::SIZE);
     let none_index = get_last_index(options::sort::NONE);
@@ -599,8 +598,7 @@ fn extract_color(options: &clap::ArgMatches) -> bool {
     let color_index = options
         .get_one::<String>(options::COLOR)
         .and_then(|_| options.indices_of(options::COLOR))
-        .map(|mut indices| indices.next_back().unwrap_or(0))
-        .unwrap_or(0);
+        .map_or(0, |mut indices| indices.next_back().unwrap_or(0));
     let unsorted_all_index = get_last_index(options::files::UNSORTED_ALL);
 
     let color_enabled = match options.get_one::<String>(options::COLOR) {

src/uu/stdbuf/src/stdbuf.rs

@@ -240,8 +240,7 @@ pub fn uumain(args: impl uucore::Args) -> UResult<()> {
                 use std::os::unix::process::ExitStatusExt;
                 let signal_msg = status
                     .signal()
-                    .map(|s| s.to_string())
-                    .unwrap_or_else(|| "unknown".to_string());
+                    .map_or_else(|| "unknown".to_string(), |s| s.to_string());
                 Err(USimpleError::new(
                     1,
                     translate!("stdbuf-error-killed-by-signal", "signal" => signal_msg),

src/uucore/src/lib/mods/locale.rs

@@ -264,8 +264,7 @@ fn create_english_bundle_from_embedded(
 fn get_message_internal(id: &str, args: Option<FluentArgs>) -> String {
     LOCALIZER.with(|lock| {
         lock.get()
-            .map(|loc| loc.format(id, args.as_ref()))
-            .unwrap_or_else(|| id.to_string()) // Return the key ID if localizer not initialized
+            .map_or_else(|| id.to_string(), |loc| loc.format(id, args.as_ref())) // Return the key ID if localizer not initialized
     })
 }