Nightly rustdoc warns about code block if it contains comments and tab

[pravic]

A code block inside documentation with rust,no_run directive:

let mut p = String::from("/path");
p.clear();	/* some comment indented with tab */

Nightly compiler throws a warning about it:

Doc-tests hello
WARNING: src\lib.rs - (line 5) Code block is not currently run as a test, but will in future versions of rustdoc. Please ensure this code block is a runnable test, or use the ignore directive.
running 0 tests
test result: ok. 0 passed; 0 failed; 0 ignored; 0 measured; 0 filtered out

And ignore doesn't help as well though.

Full sample: https://gist.github.com/anonymous/56d5eb5927c50b2a3a22f67723363f45#file-playground-rs-L5-L8

Rust version:

rustc 1.25.0-nightly (bd98fe0 2018-02-06)
binary: rustc
commit-hash: bd98fe0
commit-date: 2018-02-06
host: i686-pc-windows-msvc
release: 1.25.0-nightly
LLVM version: 4.0

[kennytm]

It is warned starting on nightly only because of #47398. If you --enable-commonmark the warnings will be emitted on 1.23.0 (stable) as well. No repro on 1.22.1 though.

cc @GuillaumeGomez

[GuillaumeGomez]

Looking what's wrong.

[GuillaumeGomez]

The warning comes if you have the following code:

/*! Sample documentation.
Just a library with some code:
```rust,no_run
let mut p = String::from("/path");
p.clear();	/* some comment */
```
*/

But not if you have:

/*! Sample documentation.

Just a library with some code:

```rust,no_run
let mut p = String::from("/path");
p.clear();	/* some comment */
```
*/

The whole issue being that hoedown doesn't recognize the first one as being a code block. I'll close this issue for now. This won't be thrown out when the new release will get out anyway since all hoedown will be removed from the compiler.

[pravic]

@GuillaumeGomez But the gist contained space between comment and code block?

[steveklabnik]

yes, re-opening since the gist does look like what is supposed to work.

[ollie27]

The issue here is that hoedown converts tabs to spaces in code blocks but pulldown-cmark doesn't so rustdoc thinks it has found a new test.

[GuillaumeGomez]

Since we don't have hoedown around anymore, can we close this issue?

[pravic]

At the moment there is no warning neither in stable nor nightly :)

[ollie27]

The issue will only affect 1.25, so it's probably too late to fix this now.

[GuillaumeGomez]

Then I close it for good!