diagnostics: avoid syntactically invalid suggestion in if conditionals

Fixes #101065

3 files changed, 51 insertions, 0 deletions

diff --git a/src/test/ui/suggestions/issue-101065.fixed b/src/test/ui/suggestions/issue-101065.fixed
new file mode 100644
index 00000000000..88c716cc86c
--- /dev/null
+++ b/src/test/ui/suggestions/issue-101065.fixed
@@ -0,0 +1,14 @@
+// check-fail
+// run-rustfix
+
+enum FakeResult<T> {
+    Ok(T)
+}
+
+fn main() {
+    let _x = if true {
+        FakeResult::Ok(FakeResult::Ok(()))
+    } else {
+        FakeResult::Ok(FakeResult::Ok(())) //~ERROR E0308
+    };
+}
diff --git a/src/test/ui/suggestions/issue-101065.rs b/src/test/ui/suggestions/issue-101065.rs
new file mode 100644
index 00000000000..2715f102708
--- /dev/null
+++ b/src/test/ui/suggestions/issue-101065.rs
@@ -0,0 +1,14 @@
+// check-fail
+// run-rustfix
+
+enum FakeResult<T> {
+    Ok(T)
+}
+
+fn main() {
+    let _x = if true {
+        FakeResult::Ok(FakeResult::Ok(()))
+    } else {
+        FakeResult::Ok(()) //~ERROR E0308
+    };
+}
diff --git a/src/test/ui/suggestions/issue-101065.stderr b/src/test/ui/suggestions/issue-101065.stderr
new file mode 100644
index 00000000000..6f7ecd24ca4
--- /dev/null
+++ b/src/test/ui/suggestions/issue-101065.stderr
@@ -0,0 +1,23 @@
+error[E0308]: `if` and `else` have incompatible types
+  --> $DIR/issue-101065.rs:12:9
+   |
+LL |       let _x = if true {
+   |  ______________-
+LL | |         FakeResult::Ok(FakeResult::Ok(()))
+   | |         ---------------------------------- expected because of this
+LL | |     } else {
+LL | |         FakeResult::Ok(())
+   | |         ^^^^^^^^^^^^^^^^^^ expected enum `FakeResult`, found `()`
+LL | |     };
+   | |_____- `if` and `else` have incompatible types
+   |
+   = note: expected enum `FakeResult<FakeResult<()>>`
+              found enum `FakeResult<()>`
+help: try wrapping the expression in `FakeResult::Ok`
+   |
+LL |         FakeResult::Ok(FakeResult::Ok(()))
+   |         +++++++++++++++                  +
+
+error: aborting due to previous error
+
+For more information about this error, try `rustc --explain E0308`.