Rollup merge of #81040 - osa1:fix_80992, r=jyn514

doctest: Reset errors before dropping the parse session

The first parse is to collect whether the code contains macros, has
`main`, and uses other crates. In that pass we ignore errors as those
will be reported when the test file is actually built.

For that we need to reset errors in the `Diagnostic` otherwise when
dropping it unhandled errors will be reported as compiler bugs.

Fixes #80992

3 files changed, 23 insertions, 0 deletions

diff --git a/src/librustdoc/doctest.rs b/src/librustdoc/doctest.rs
index cf51162cfb5..3de97f2dd2e 100644
--- a/src/librustdoc/doctest.rs
+++ b/src/librustdoc/doctest.rs
@@ -500,6 +500,12 @@ crate fn make_test(
                 }
             }
 
+            // Reset errors so that they won't be reported as compiler bugs when dropping the
+            // handler. Any errors in the tests will be reported when the test file is compiled,
+            // Note that we still need to cancel the errors above otherwise `DiagnosticBuilder`
+            // will panic on drop.
+            sess.span_diagnostic.reset_err_count();
+
             (found_main, found_extern_crate, found_macro)
         })
     });
diff --git a/src/test/rustdoc-ui/issue-80992.rs b/src/test/rustdoc-ui/issue-80992.rs
new file mode 100644
index 00000000000..8983439bb64
--- /dev/null
+++ b/src/test/rustdoc-ui/issue-80992.rs
@@ -0,0 +1,11 @@
+// check-pass
+// compile-flags:--test
+// normalize-stdout-test: "src/test/rustdoc-ui" -> "$$DIR"
+// normalize-stdout-test "finished in \d+\.\d+s" -> "finished in $$TIME"
+
+pub fn test() -> Result<(), ()> {
+    //! ```compile_fail
+    //! fn test() -> Result< {}
+    //! ```
+    Ok(())
+}
diff --git a/src/test/rustdoc-ui/issue-80992.stdout b/src/test/rustdoc-ui/issue-80992.stdout
new file mode 100644
index 00000000000..1dd19f46827
--- /dev/null
+++ b/src/test/rustdoc-ui/issue-80992.stdout
@@ -0,0 +1,6 @@
+
+running 1 test
+test $DIR/issue-80992.rs - test (line 7) ... ok
+
+test result: ok. 1 passed; 0 failed; 0 ignored; 0 measured; 0 filtered out; finished in $TIME
+