Auto merge of #86197 - FabianWolff:trailing-whitespace, r=JohnTitor

Remove unnecessary trailing whitespace from error messages

Some error messages currently contain unnecessary trailing whitespace. There are some legitimate reasons for having trailing whitespace in the output, such as for uniform indentation of possibly-empty input lines, but the whitespace I have addressed here occurs in a line used only for spacing, and I see no reason why that should have trailing whitespace (spacing lines inserted in other places also don't have trailing whitespace).

I have also removed a superfluous call to `buffer.putc()`, which has no effect because the same character is already placed there by `draw_col_separator()`.

Use `git diff --ignore-space-at-eol` to see my changes; otherwise the diff is quite large due to the whitespace removed from expected outputs in `src/test/ui/`.

Author: bors

compiler/rustc_errors/src/emitter.rs

@@ -954,7 +954,6 @@ impl EmitterWriter {
         //   |
         for pos in 0..=line_len {
             draw_col_separator(buffer, line_offset + pos + 1, width_offset - 2);
-            buffer.putc(line_offset + pos + 1, width_offset - 2, '|', Style::LineNumber);
         }
 
         // Write the horizontal lines for multiline annotations
@@ -1344,7 +1343,11 @@ impl EmitterWriter {
                 let buffer_msg_line_offset = buffer.num_lines();
 
                 // Add spacing line
-                draw_col_separator(&mut buffer, buffer_msg_line_offset, max_line_num_len + 1);
+                draw_col_separator_no_space(
+                    &mut buffer,
+                    buffer_msg_line_offset,
+                    max_line_num_len + 1,
+                );
 
                 // Then, the secondary file indicator
                 buffer.prepend(buffer_msg_line_offset + 1, "::: ", Style::LineNumber);

src/test/ui/associated-type-bounds/bad-bounds-on-assoc-in-trait.stderr

@@ -3,7 +3,7 @@ error[E0277]: `<<Self as Case1>::C as Iterator>::Item` cannot be sent between th
    |
 LL |     type C: Clone + Iterator<Item: Send + Iterator<Item: for<'a> Lam<&'a u8, App: Debug>> + Sync>;
    |                                    ^^^^ `<<Self as Case1>::C as Iterator>::Item` cannot be sent between threads safely
-   | 
+   |
   ::: $SRC_DIR/core/src/marker.rs:LL:COL
    |
 LL | pub unsafe auto trait Send {
@@ -20,7 +20,7 @@ error[E0277]: `<<Self as Case1>::C as Iterator>::Item` is not an iterator
    |
 LL |     type C: Clone + Iterator<Item: Send + Iterator<Item: for<'a> Lam<&'a u8, App: Debug>> + Sync>;
    |                                           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ `<<Self as Case1>::C as Iterator>::Item` is not an iterator
-   | 
+   |
   ::: $SRC_DIR/core/src/iter/traits/iterator.rs:LL:COL
    |
 LL | pub trait Iterator {
@@ -37,7 +37,7 @@ error[E0277]: `<<Self as Case1>::C as Iterator>::Item` cannot be shared between
    |
 LL |     type C: Clone + Iterator<Item: Send + Iterator<Item: for<'a> Lam<&'a u8, App: Debug>> + Sync>;
    |                                                                                             ^^^^ `<<Self as Case1>::C as Iterator>::Item` cannot be shared between threads safely
-   | 
+   |
   ::: $SRC_DIR/core/src/marker.rs:LL:COL
    |
 LL | pub unsafe auto trait Sync {