Increase spacing for suggestions in diagnostics

Make the spacing between the code snippet and verbose structured
suggestions consistent with note and help messages.

Author: estebank

src/librustc_errors/emitter.rs

@@ -1629,6 +1629,19 @@ impl EmitterWriter {
                             _ => ()
                         }
                     }
+                    if children.is_empty() && suggestions.iter().any(|s| {
+                        s.style != SuggestionStyle::CompletelyHidden
+                    }) {
+                        let mut buffer = StyledBuffer::new();
+                        if !self.short_message {
+                            draw_col_separator_no_space(&mut buffer, 0, max_line_num_len + 1);
+                        }
+                        match emit_to_destination(&buffer.render(), level, &mut self.dst,
+                                                self.short_message) {
+                            Ok(()) => (),
+                            Err(e) => panic!("failed to emit error: {}", e)
+                        }
+                    }
                     for sugg in suggestions {
                         if sugg.style == SuggestionStyle::CompletelyHidden {
                             // do not display this suggestion, it is meant only for tools

src/test/rustdoc-ui/intra-links-ambiguity.stderr

@@ -23,6 +23,7 @@ error: `ambiguous` is both a struct and a function
    |
 LL | /// [ambiguous] is ambiguous.
    |      ^^^^^^^^^ ambiguous link
+   |
 help: to link to the struct, prefix with the item type
    |
 LL | /// [struct@ambiguous] is ambiguous.
@@ -37,6 +38,7 @@ error: `multi_conflict` is a struct, a function, and a macro
    |
 LL | /// [`multi_conflict`] is a three-way conflict.
    |      ^^^^^^^^^^^^^^^^ ambiguous link
+   |
 help: to link to the struct, prefix with the item type
    |
 LL | /// [`struct@multi_conflict`] is a three-way conflict.
@@ -55,6 +57,7 @@ error: `type_and_value` is both a module and a constant
    |
 LL | /// Ambiguous [type_and_value].
    |                ^^^^^^^^^^^^^^ ambiguous link
+   |
 help: to link to the module, prefix with the item type
    |
 LL | /// Ambiguous [module@type_and_value].
@@ -69,6 +72,7 @@ error: `foo::bar` is both an enum and a function
    |
 LL | /// Ambiguous non-implied shortcut link [`foo::bar`].
    |                                          ^^^^^^^^^^ ambiguous link
+   |
 help: to link to the enum, prefix with the item type
    |
 LL | /// Ambiguous non-implied shortcut link [`enum@foo::bar`].

src/test/rustdoc-ui/invalid-syntax.stderr

@@ -24,6 +24,7 @@ LL |   /// ```
 LL | | /// \__________pkt->size___________/          \_result->size_/ \__pkt->size__/
 LL | | /// ```
    | |_______^
+   |
 help: mark blocks that do not contain Rust code as text
    |
 LL | /// ```text
@@ -34,6 +35,7 @@ error: unknown start of token: `
   |
 3 |    |     ^^^^^^ did you mean `baz::foobar`?
   |                              ^
+  |
 help: Unicode character '`' (Grave Accent) looks like ''' (Single Quote), but it is not
   |
 3 |    |     ^^^^^^ did you mean 'baz::foobar`?
@@ -44,6 +46,7 @@ error: unknown start of token: `
   |
 3 |    |     ^^^^^^ did you mean `baz::foobar`?
   |                                          ^
+  |
 help: Unicode character '`' (Grave Accent) looks like ''' (Single Quote), but it is not
   |
 3 |    |     ^^^^^^ did you mean `baz::foobar'?
@@ -59,6 +62,7 @@ LL | | /// LL | use foobar::Baz;
 LL | | ///    |     ^^^^^^ did you mean `baz::foobar`?
 LL | | /// ```
    | |_______^
+   |
 help: mark blocks that do not contain Rust code as text
    |
 LL | /// ```text
@@ -78,6 +82,7 @@ LL |   /// ```
 LL | | /// \_
 LL | | /// ```
    | |_______^
+   |
 help: mark blocks that do not contain Rust code as text
    |
 LL | /// ```text
@@ -117,6 +122,7 @@ error: unknown start of token: `
   |
 1 | ```
   | ^
+  |
 help: Unicode character '`' (Grave Accent) looks like ''' (Single Quote), but it is not
   |
 1 | '``
@@ -127,6 +133,7 @@ error: unknown start of token: `
   |
 1 | ```
   |  ^
+  |
 help: Unicode character '`' (Grave Accent) looks like ''' (Single Quote), but it is not
   |
 1 | `'`
@@ -137,6 +144,7 @@ error: unknown start of token: `
   |
 1 | ```
   |   ^
+  |
 help: Unicode character '`' (Grave Accent) looks like ''' (Single Quote), but it is not
   |
 1 | ``'
@@ -196,6 +204,7 @@ LL | | ///
 LL | | ///
 LL | | /// ```
    | |_______^
+   |
 help: mark blocks that do not contain Rust code as text
    |
 LL | /// ```text
@@ -236,6 +245,7 @@ error: unknown start of token: `
   |
 1 | ```
   | ^
+  |
 help: Unicode character '`' (Grave Accent) looks like ''' (Single Quote), but it is not
   |
 1 | '``
@@ -264,6 +274,7 @@ error: unknown start of token: `
   |
 3 |    |     ^^^^^^ did you mean `baz::foobar`?
   |                              ^
+  |
 help: Unicode character '`' (Grave Accent) looks like ''' (Single Quote), but it is not
   |
 3 |    |     ^^^^^^ did you mean 'baz::foobar`?

src/test/ui/associated-types/associated-types-path-2.stderr

@@ -3,6 +3,7 @@ error[E0308]: mismatched types
    |
 LL |     f1(2i32, 4i32);
    |              ^^^^ expected u32, found i32
+   |
 help: change the type of the numeric literal from `i32` to `u32`
    |
 LL |     f1(2i32, 4u32);
@@ -43,6 +44,7 @@ error[E0308]: mismatched types
    |
 LL |     let _: i32 = f2(2i32);
    |                  ^^^^^^^^ expected i32, found u32
+   |
 help: you can convert an `u32` to `i32` and panic if the converted value wouldn't fit
    |
 LL |     let _: i32 = f2(2i32).try_into().unwrap();

src/test/ui/async-await/await-keyword/2018-edition-error-in-non-macro-position.stderr

@@ -3,6 +3,7 @@ error: expected identifier, found keyword `await`
    |
 LL |     pub mod await {
    |             ^^^^^ expected identifier, found keyword
+   |
 help: you can escape reserved keywords to use them as identifiers
    |
 LL |     pub mod r#await {
@@ -13,6 +14,7 @@ error: expected identifier, found keyword `await`
    |
 LL |         pub struct await;
    |                    ^^^^^ expected identifier, found keyword
+   |
 help: you can escape reserved keywords to use them as identifiers
    |
 LL |         pub struct r#await;
@@ -23,6 +25,7 @@ error: expected identifier, found keyword `await`
    |
 LL | use self::outer_mod::await::await;
    |                      ^^^^^ expected identifier, found keyword
+   |
 help: you can escape reserved keywords to use them as identifiers
    |
 LL | use self::outer_mod::r#await::await;
@@ -33,6 +36,7 @@ error: expected identifier, found keyword `await`
    |
 LL | use self::outer_mod::await::await;
    |                             ^^^^^ expected identifier, found keyword
+   |
 help: you can escape reserved keywords to use them as identifiers
    |
 LL | use self::outer_mod::await::r#await;
@@ -43,6 +47,7 @@ error: expected identifier, found keyword `await`
    |
 LL | struct Foo { await: () }
    |              ^^^^^ expected identifier, found keyword
+   |
 help: you can escape reserved keywords to use them as identifiers
    |
 LL | struct Foo { r#await: () }
@@ -53,6 +58,7 @@ error: expected identifier, found keyword `await`
    |
 LL | impl Foo { fn await() {} }
    |               ^^^^^ expected identifier, found keyword
+   |
 help: you can escape reserved keywords to use them as identifiers
    |
 LL | impl Foo { fn r#await() {} }
@@ -63,6 +69,7 @@ error: expected identifier, found keyword `await`
    |
 LL | macro_rules! await {
    |              ^^^^^ expected identifier, found keyword
+   |
 help: you can escape reserved keywords to use them as identifiers
    |
 LL | macro_rules! r#await {

src/test/ui/async-await/await-keyword/2018-edition-error.stderr

@@ -3,6 +3,7 @@ error: expected identifier, found keyword `await`
    |
 LL |     pub mod await {
    |             ^^^^^ expected identifier, found keyword
+   |
 help: you can escape reserved keywords to use them as identifiers
    |
 LL |     pub mod r#await {
@@ -13,6 +14,7 @@ error: expected identifier, found keyword `await`
    |
 LL |         pub struct await;
    |                    ^^^^^ expected identifier, found keyword
+   |
 help: you can escape reserved keywords to use them as identifiers
    |
 LL |         pub struct r#await;
@@ -23,6 +25,7 @@ error: expected identifier, found keyword `await`
    |
 LL | use self::outer_mod::await::await;
    |                      ^^^^^ expected identifier, found keyword
+   |
 help: you can escape reserved keywords to use them as identifiers
    |
 LL | use self::outer_mod::r#await::await;
@@ -33,6 +36,7 @@ error: expected identifier, found keyword `await`
    |
 LL | use self::outer_mod::await::await;
    |                             ^^^^^ expected identifier, found keyword
+   |
 help: you can escape reserved keywords to use them as identifiers
    |
 LL | use self::outer_mod::await::r#await;
@@ -43,6 +47,7 @@ error: expected identifier, found keyword `await`
    |
 LL | macro_rules! await { () => {}; }
    |              ^^^^^ expected identifier, found keyword
+   |
 help: you can escape reserved keywords to use them as identifiers
    |
 LL | macro_rules! r#await { () => {}; }

src/test/ui/async-await/no-const-async.stderr

@@ -3,6 +3,7 @@ error: expected identifier, found keyword `async`
    |
 LL | pub const async fn x() {}
    |           ^^^^^ expected identifier, found keyword
+   |
 help: you can escape reserved keywords to use them as identifiers
    |
 LL | pub const r#async fn x() {}

src/test/ui/bad/bad-crate-name.stderr

@@ -3,6 +3,7 @@ error: crate name using dashes are not valid in `extern crate` statements
    |
 LL | extern crate krate-name-here;
    |              ^^^^^^^^^^^^^^^ dash-separated idents are not valid
+   |
 help: if the original crate name uses dashes you need to use underscores in the code
    |
 LL | extern crate krate_name_here;

src/test/ui/borrowck/borrowck-vec-pattern-nesting.stderr

@@ -33,6 +33,7 @@ LL |         &mut [_a,
    |               |
    |               data moved here
    |               move occurs because `_a` has type `std::boxed::Box<isize>`, which does not implement the `Copy` trait
+   |
 help: consider removing the `&mut`
    |
 LL |         [_a,
@@ -64,6 +65,7 @@ LL |          _b] => {}
    |          |
    |          data moved here
    |          move occurs because `_b` has type `std::boxed::Box<isize>`, which does not implement the `Copy` trait
+   |
 help: consider removing the `&mut`
    |
 LL |         [

src/test/ui/class-missing-self.stderr

@@ -9,6 +9,7 @@ error[E0425]: cannot find function `sleep` in this scope
    |
 LL |       sleep();
    |       ^^^^^ not found in this scope
+   |
 help: possible candidate is found in another module, you can import it into scope
    |
 LL | use std::thread::sleep;