clippy: fix assigning_clones lint

https://rust-lang.github.io/rust-clippy/rust-1.95.0/index.html#assigning_clones

src/sed/compiler.rs

@@ -120,7 +120,7 @@ fn patch_block_endings(head: Option<Rc<RefCell<Command>>>) {
                 }
 
                 // 3) splice the tail’s `.next` to splice_target
-                tail.borrow_mut().next = splice_target.clone();
+                tail.borrow_mut().next.clone_from(&splice_target);
             }
 
             // drop the borrow before moving on
@@ -140,7 +140,7 @@ fn populate_label_map(
     mut cur: Option<Rc<RefCell<Command>>>,
     context: &mut ProcessingContext,
 ) -> UResult<()> {
-    while let Some(rc_cmd) = cur {
+    while let Some(rc_cmd) = cur.take() {
         // Borrow mutably just long enough to inspect/rewire this node
         let cmd = rc_cmd.borrow_mut();
 
@@ -163,14 +163,14 @@ fn populate_label_map(
             context.label_to_command_map.insert(label, rc_cmd.clone());
         }
 
-        cur = cmd.next.clone();
+        cur.clone_from(&cmd.next);
     }
     Ok(())
 }
 
 /// Populate the context's address range command list with references to associated commands.
 fn populate_range_commands(mut cur: Option<Rc<RefCell<Command>>>, context: &mut ProcessingContext) {
-    while let Some(rc_cmd) = cur {
+    while let Some(rc_cmd) = cur.take() {
         // Borrow mutably just long enough to inspect/rewire this node
         let cmd = rc_cmd.borrow_mut();
 
@@ -184,7 +184,7 @@ fn populate_range_commands(mut cur: Option<Rc<RefCell<Command>>>, context: &mut
             context.range_commands.push(Rc::clone(&rc_cmd));
         }
 
-        cur = cmd.next.clone();
+        cur.clone_from(&cmd.next);
     }
 }
 
@@ -194,7 +194,7 @@ fn resolve_branch_targets(
     mut cur: Option<Rc<RefCell<Command>>>,
     context: &mut ProcessingContext,
 ) -> UResult<()> {
-    while let Some(rc_cmd) = cur {
+    while let Some(rc_cmd) = cur.take() {
         // Borrow mutably just long enough to inspect/rewire this node
         let mut cmd = rc_cmd.borrow_mut();
 
@@ -233,7 +233,7 @@ fn resolve_branch_targets(
         }
 
         // Advance to the next sibling
-        cur = cmd.next.clone();
+        cur.clone_from(&cmd.next);
     }
     Ok(())
 }

src/sed/processor.rs

@@ -444,12 +444,12 @@ fn process_file(
             };
 
         // Loop over script commands.
-        while let Some(command_rc) = current {
+        while let Some(command_rc) = current.take() {
             let mut command = command_rc.borrow_mut();
 
             if !applies(&mut command, reader, &mut pattern, context)? {
                 // Advance to next command
-                current = command.next.clone();
+                current.clone_from(&command.next);
                 continue;
             }
 
@@ -457,7 +457,7 @@ fn process_file(
                 '{' => {
                     // Block begin; start processing the enclosed ones.
                     let body = extract_variant!(command, BranchTarget);
-                    current = body.clone();
+                    current.clone_from(body);
                     continue;
                 }
                 '}' => {
@@ -475,7 +475,7 @@ fn process_file(
                     let target = extract_variant!(command, BranchTarget);
                     if target.is_some() {
                         // New command to execute
-                        current = target.clone();
+                        current.clone_from(target);
                         continue;
                     } else {
                         // Branch to the end of the script.
@@ -502,7 +502,7 @@ fn process_file(
                     if let Some(pos) = pattern.as_str()?.find('\n') {
                         let (s, _) = pattern.fields_mut()?;
                         s.drain(..=pos);
-                        current = commands.clone();
+                        current.clone_from(&commands);
                         continue;
                     } else {
                         // Same as d
@@ -598,7 +598,7 @@ fn process_file(
                     context.substitution_made = false;
                     if target.is_some() {
                         // New command to execute
-                        current = target.clone();
+                        current.clone_from(target);
                         continue;
                     } else {
                         // Branch to the end of the script.
@@ -635,7 +635,7 @@ fn process_file(
                 _ => panic!("invalid command code"),
             } // match
             // Advance to next command.
-            current = command.next.clone();
+            current.clone_from(&command.next);
         }
 
         if !context.quiet {