Auto merge of #101757 - Dylan-DPC:rollup-wkt6oe9, r=Dylan-DPC

Rollup of 5 pull requests

Successful merges:

 - #101602 (Streamline `AttrAnnotatedTokenStream`)
 - #101690 (Avoid `Iterator::last`)
 - #101700 (A `SubstitutionPart` is not considered a deletion if it replaces nothing with nothing)
 - #101745 (Fix typo in concat_bytes documentation)
 - #101748 (rustdoc: remove redundant CSS `#source-sidebar, #sidebar-toggle`)

Failed merges:

r? `@ghost`
`@rustbot` modify labels: rollup

1 files changed, 9 insertions, 10 deletions

diff --git a/compiler/rustc_errors/src/lib.rs b/compiler/rustc_errors/src/lib.rs
index fb7ae6f99cf..888128f3f74 100644
--- a/compiler/rustc_errors/src/lib.rs
+++ b/compiler/rustc_errors/src/lib.rs
@@ -150,21 +150,20 @@ pub struct SubstitutionHighlight {
 
 impl SubstitutionPart {
     pub fn is_addition(&self, sm: &SourceMap) -> bool {
-        !self.snippet.is_empty()
-            && sm
-                .span_to_snippet(self.span)
-                .map_or(self.span.is_empty(), |snippet| snippet.trim().is_empty())
+        !self.snippet.is_empty() && !self.replaces_meaningful_content(sm)
     }
 
-    pub fn is_deletion(&self) -> bool {
-        self.snippet.trim().is_empty()
+    pub fn is_deletion(&self, sm: &SourceMap) -> bool {
+        self.snippet.trim().is_empty() && self.replaces_meaningful_content(sm)
     }
 
     pub fn is_replacement(&self, sm: &SourceMap) -> bool {
-        !self.snippet.is_empty()
-            && sm
-                .span_to_snippet(self.span)
-                .map_or(!self.span.is_empty(), |snippet| !snippet.trim().is_empty())
+        !self.snippet.is_empty() && self.replaces_meaningful_content(sm)
+    }
+
+    fn replaces_meaningful_content(&self, sm: &SourceMap) -> bool {
+        sm.span_to_snippet(self.span)
+            .map_or(!self.span.is_empty(), |snippet| !snippet.trim().is_empty())
     }
 }