rustdoc runs some markdown tests twice #42726
Description
Running rustdoc --test with 1.18.0 and nightly on the following markdown file:
# Foo ``` fail1 ``` ``` fail2 ``` bar ``` fail3 ```Produces the following:
output
running 5 tests test foo.md - Foo (line 3) ... FAILED test foo.md - Foo (line 7) ... FAILED test foo.md - Foo (line 12) ... FAILED test foo.md - Foo (line 8) ... FAILED test foo.md - Foo (line 3) ... FAILED failures: ---- foo.md - Foo (line 3) stdout ---- error[E0425]: cannot find value `fail1` in this scope --> <anon>:2:1 | 2 | fail1 | ^^^^^ not found in this scope error: aborting due to previous error(s) thread 'rustc' panicked at 'Box<Any>', src\librustc\session\mod.rs:218 note: Run with `RUST_BACKTRACE=1` for a backtrace. ---- foo.md - Foo (line 7) stdout ---- error[E0425]: cannot find value `fail2` in this scope --> <anon>:2:1 | 2 | fail2 | ^^^^^ not found in this scope error: aborting due to previous error(s) thread 'rustc' panicked at 'Box<Any>', src\librustc\session\mod.rs:218 ---- foo.md - Foo (line 12) stdout ---- error[E0425]: cannot find value `fail3` in this scope --> <anon>:2:1 | 2 | fail3 | ^^^^^ not found in this scope error: aborting due to previous error(s) thread 'rustc' panicked at 'Box<Any>', src\librustc\session\mod.rs:218 ---- foo.md - Foo (line 8) stdout ---- error[E0425]: cannot find value `fail2` in this scope --> <anon>:2:1 | 2 | fail2 | ^^^^^ not found in this scope error: aborting due to previous error(s) thread 'rustc' panicked at 'Box<Any>', src\librustc\session\mod.rs:218 ---- foo.md - Foo (line 3) stdout ---- error[E0425]: cannot find value `fail1` in this scope --> <anon>:2:1 | 2 | fail1 | ^^^^^ not found in this scope error: aborting due to previous error(s) thread 'rustc' panicked at 'Box<Any>', src\librustc\session\mod.rs:218 failures: foo.md - Foo (line 12) foo.md - Foo (line 3) foo.md - Foo (line 3) foo.md - Foo (line 7) foo.md - Foo (line 8) test result: FAILED. 0 passed; 5 failed; 0 ignored; 0 measured; 0 filtered out The first 2 tests are run twice (one with the wrong line number though). The last test is only run once. It looks as though it's running all the tests found by hoedown and all the tests run by pulldown-cmark. I'm pretty sure this wasn't the intention of #41290 and #41431 cc. @GuillaumeGomez. Note that this doesn't happen for tests in rust files.
This is also technically a stable to stable regression because the following file passes rustdoc --test on 1.17.0 but not on 1.18.0 or later:
# Foo bar ``` fail3 ```