Auto merge of rust-lang#3973 - nipunn1313:readme2, r=Turbo87

Support relative URLs from repo-subdirectory packages

Extract `.cargo_vcs_info.json` from the tarball and use it to determine the path in vcs.

Support for this was added to cargo with
rust-lang/cargo#9866

Fixes rust-lang#3484
(note that support for this in admin::render_readmes not yet exists - would come with rust-lang#4095)

Depends on rust-lang#4097 (Because of community/community#4477 - github ends up rendering the diffs together. Go to the commits tab and just look at the most recent commits to review).

Author: bors

cargo-registry-markdown/lib.rs

@@ -245,18 +245,23 @@ static MARKDOWN_EXTENSIONS: [&str; 7] =
 /// use cargo_registry_markdown::text_to_html;
 ///
 /// let text = "[Rust](https://rust-lang.org/) is an awesome *systems programming* language!";
-/// let rendered = text_to_html(text, "README.md", None);
+/// let rendered = text_to_html(text, "README.md", None, None);
 /// assert_eq!(rendered, "<p><a href=\"https://rust-lang.org/\" rel=\"nofollow noopener noreferrer\">Rust</a> is an awesome <em>systems programming</em> language!</p>\n");
 /// ```
-pub fn text_to_html(text: &str, path: &str, base_url: Option<&str>) -> String {
-    let path = Path::new(path);
-    let base_dir = path.parent().and_then(|p| p.to_str()).unwrap_or("");
-
-    if path.extension().is_none() {
+pub fn text_to_html(
+    text: &str,
+    readme_path_in_pkg: &str,
+    base_url: Option<&str>,
+    pkg_path_in_vcs: Option<&str>,
+) -> String {
+    let path_in_vcs = Path::new(pkg_path_in_vcs.unwrap_or("")).join(readme_path_in_pkg);
+    let base_dir = path_in_vcs.parent().and_then(|p| p.to_str()).unwrap_or("");
+
+    if path_in_vcs.extension().is_none() {
         return markdown_to_html(text, base_url, base_dir);
     }
 
-    if let Some(ext) = path.extension().and_then(|ext| ext.to_str()) {
+    if let Some(ext) = path_in_vcs.extension().and_then(|ext| ext.to_str()) {
         if MARKDOWN_EXTENSIONS.contains(&ext.to_lowercase().as_str()) {
             return markdown_to_html(text, base_url, base_dir);
         }
@@ -477,30 +482,38 @@ mod tests {
             "s1/s2/readme.md",
         ] {
             assert_eq!(
-                text_to_html("*lobster*", f, None),
+                text_to_html("*lobster*", f, None, None),
                 "<p><em>lobster</em></p>\n"
             );
         }
 
         assert_eq!(
-            text_to_html("*[lobster](docs/lobster)*", "readme.md", Some("https://github.com/rust-lang/test")),
+            text_to_html("*[lobster](docs/lobster)*", "readme.md", Some("https://github.com/rust-lang/test"), None),
             "<p><em><a href=\"https://github.com/rust-lang/test/blob/HEAD/docs/lobster\" rel=\"nofollow noopener noreferrer\">lobster</a></em></p>\n"
         );
         assert_eq!(
-            text_to_html("*[lobster](docs/lobster)*", "s/readme.md", Some("https://github.com/rust-lang/test")),
+            text_to_html("*[lobster](docs/lobster)*", "s/readme.md", Some("https://github.com/rust-lang/test"), None),
             "<p><em><a href=\"https://github.com/rust-lang/test/blob/HEAD/s/docs/lobster\" rel=\"nofollow noopener noreferrer\">lobster</a></em></p>\n"
         );
         assert_eq!(
-            text_to_html("*[lobster](docs/lobster)*", "s1/s2/readme.md", Some("https://github.com/rust-lang/test")),
+            text_to_html("*[lobster](docs/lobster)*", "s1/s2/readme.md", Some("https://github.com/rust-lang/test"), None),
             "<p><em><a href=\"https://github.com/rust-lang/test/blob/HEAD/s1/s2/docs/lobster\" rel=\"nofollow noopener noreferrer\">lobster</a></em></p>\n"
         );
+        assert_eq!(
+            text_to_html("*[lobster](docs/lobster)*", "s1/s2/readme.md", Some("https://github.com/rust-lang/test"), Some("path/in/vcs/")),
+            "<p><em><a href=\"https://github.com/rust-lang/test/blob/HEAD/path/in/vcs/s1/s2/docs/lobster\" rel=\"nofollow noopener noreferrer\">lobster</a></em></p>\n"
+        );
+        assert_eq!(
+            text_to_html("*[lobster](docs/lobster)*", "s1/s2/readme.md", Some("https://github.com/rust-lang/test"), Some("path/in/vcs")),
+            "<p><em><a href=\"https://github.com/rust-lang/test/blob/HEAD/path/in/vcs/s1/s2/docs/lobster\" rel=\"nofollow noopener noreferrer\">lobster</a></em></p>\n"
+        );
     }
 
     #[test]
     fn text_to_html_renders_other_things() {
         for f in &["readme.exe", "readem.org", "blah.adoc"] {
             assert_eq!(
-                text_to_html("<script>lobster</script>\n\nis my friend\n", f, None),
+                text_to_html("<script>lobster</script>\n\nis my friend\n", f, None, None),
                 "&lt;script&gt;lobster&lt;/script&gt;<br>\n<br>\nis my friend<br>\n"
             );
         }

src/admin/render_readmes.rs

@@ -205,10 +205,15 @@ fn render_pkg_readme<R: Read>(mut archive: Archive<R>, pkg_name: &str) -> anyhow
         let contents = find_file_by_path(&mut entries, Path::new(&path))
             .with_context(|| format!("Failed to read {} file", readme_path))?;
 
+        // pkg_path_in_vcs Unsupported from admin::render_readmes. See #4095
+        // Would need access to cargo_vcs_info
+        let pkg_path_in_vcs = None;
+
         text_to_html(
             &contents,
             &readme_path,
             manifest.package.repository.as_deref(),
+            pkg_path_in_vcs,
         )
     };
     return Ok(rendered);

src/controllers/krate/publish.rs

@@ -5,6 +5,7 @@ use hex::ToHex;
 use sha2::{Digest, Sha256};
 use std::collections::HashMap;
 use std::io::Read;
+use std::path::Path;
 use std::sync::Arc;
 use swirl::Job;
 
@@ -18,7 +19,7 @@ use crate::worker;
 
 use crate::schema::*;
 use crate::util::errors::{cargo_err, AppResult};
-use crate::util::{read_fill, read_le_u32, LimitErrorReader, Maximums};
+use crate::util::{read_fill, read_le_u32, CargoVcsInfo, LimitErrorReader, Maximums};
 use crate::views::{
     EncodableCrate, EncodableCrateDependency, EncodableCrateUpload, GoodCrate, PublishWarnings,
 };
@@ -195,7 +196,8 @@ pub fn publish(req: &mut dyn RequestExt) -> EndpointResult {
         LimitErrorReader::new(req.body(), maximums.max_upload_size).read_to_end(&mut tarball)?;
         let hex_cksum: String = Sha256::digest(&tarball).encode_hex();
         let pkg_name = format!("{}-{}", krate.name, vers);
-        verify_tarball(&pkg_name, &tarball, maximums.max_unpack_size)?;
+        let cargo_vcs_info = verify_tarball(&pkg_name, &tarball, maximums.max_unpack_size)?;
+        let pkg_path_in_vcs = cargo_vcs_info.map(|info| info.path_in_vcs);
 
         if let Some(readme) = new_crate.readme {
             worker::render_and_upload_readme(
@@ -205,6 +207,7 @@ pub fn publish(req: &mut dyn RequestExt) -> EndpointResult {
                     .readme_file
                     .unwrap_or_else(|| String::from("README.md")),
                 repo,
+                pkg_path_in_vcs,
             )
             .enqueue(&conn)?;
         }
@@ -379,7 +382,11 @@ pub fn add_dependencies(
     Ok(git_deps)
 }
 
-fn verify_tarball(pkg_name: &str, tarball: &[u8], max_unpack: u64) -> AppResult<()> {
+fn verify_tarball(
+    pkg_name: &str,
+    tarball: &[u8],
+    max_unpack: u64,
+) -> AppResult<Option<CargoVcsInfo>> {
     // All our data is currently encoded with gzip
     let decoder = GzDecoder::new(tarball);
 
@@ -389,8 +396,12 @@ fn verify_tarball(pkg_name: &str, tarball: &[u8], max_unpack: u64) -> AppResult<
 
     // Use this I/O object now to take a peek inside
     let mut archive = tar::Archive::new(decoder);
+
+    let vcs_info_path = Path::new(&pkg_name).join(".cargo_vcs_info.json");
+    let mut vcs_info = None;
+
     for entry in archive.entries()? {
-        let entry = entry.map_err(|err| {
+        let mut entry = entry.map_err(|err| {
             err.chain(cargo_err(
                 "uploaded tarball is malformed or too large when decompressed",
             ))
@@ -401,9 +412,15 @@ fn verify_tarball(pkg_name: &str, tarball: &[u8], max_unpack: u64) -> AppResult<
         // upload a tarball that contains both `foo-0.1.0/` source code as well
         // as `bar-0.1.0/` source code, and this could overwrite other crates in
         // the registry!
-        if !entry.path()?.starts_with(&pkg_name) {
+        let entry_path = entry.path()?;
+        if !entry_path.starts_with(&pkg_name) {
             return Err(cargo_err("invalid tarball uploaded"));
         }
+        if entry_path == vcs_info_path {
+            let mut contents = String::new();
+            entry.read_to_string(&mut contents)?;
+            vcs_info = CargoVcsInfo::from_contents(&contents).ok();
+        }
 
         // Historical versions of the `tar` crate which Cargo uses internally
         // don't properly prevent hard links and symlinks from overwriting
@@ -415,7 +432,7 @@ fn verify_tarball(pkg_name: &str, tarball: &[u8], max_unpack: u64) -> AppResult<
             return Err(cargo_err("invalid tarball uploaded"));
         }
     }
-    Ok(())
+    Ok(vcs_info)
 }
 
 #[cfg(test)]
@@ -435,14 +452,57 @@ mod tests {
     #[test]
     fn verify_tarball_test() {
         let mut pkg = tar::Builder::new(vec![]);
-        add_file(&mut pkg, "foo-0.0.1/.cargo_vcs_info.json", br#"{}"#);
+        add_file(&mut pkg, "foo-0.0.1/Cargo.toml", b"");
         let mut serialized_archive = vec![];
         GzEncoder::new(pkg.into_inner().unwrap().as_slice(), Default::default())
             .read_to_end(&mut serialized_archive)
             .unwrap();
 
         let limit = 512 * 1024 * 1024;
-        assert_ok!(verify_tarball("foo-0.0.1", &serialized_archive, limit));
+        assert_eq!(
+            verify_tarball("foo-0.0.1", &serialized_archive, limit).unwrap(),
+            None
+        );
         assert_err!(verify_tarball("bar-0.0.1", &serialized_archive, limit));
     }
+
+    #[test]
+    fn verify_tarball_test_incomplete_vcs_info() {
+        let mut pkg = tar::Builder::new(vec![]);
+        add_file(&mut pkg, "foo-0.0.1/Cargo.toml", b"");
+        add_file(
+            &mut pkg,
+            "foo-0.0.1/.cargo_vcs_info.json",
+            br#"{"unknown": "field"}"#,
+        );
+        let mut serialized_archive = vec![];
+        GzEncoder::new(pkg.into_inner().unwrap().as_slice(), Default::default())
+            .read_to_end(&mut serialized_archive)
+            .unwrap();
+        let limit = 512 * 1024 * 1024;
+        let vcs_info = verify_tarball("foo-0.0.1", &serialized_archive, limit)
+            .unwrap()
+            .unwrap();
+        assert_eq!(vcs_info.path_in_vcs, "");
+    }
+
+    #[test]
+    fn verify_tarball_test_vcs_info() {
+        let mut pkg = tar::Builder::new(vec![]);
+        add_file(&mut pkg, "foo-0.0.1/Cargo.toml", b"");
+        add_file(
+            &mut pkg,
+            "foo-0.0.1/.cargo_vcs_info.json",
+            br#"{"path_in_vcs": "path/in/vcs"}"#,
+        );
+        let mut serialized_archive = vec![];
+        GzEncoder::new(pkg.into_inner().unwrap().as_slice(), Default::default())
+            .read_to_end(&mut serialized_archive)
+            .unwrap();
+        let limit = 512 * 1024 * 1024;
+        let vcs_info = verify_tarball("foo-0.0.1", &serialized_archive, limit)
+            .unwrap()
+            .unwrap();
+        assert_eq!(vcs_info.path_in_vcs, "path/in/vcs");
+    }
 }

src/util.rs

@@ -53,3 +53,46 @@ impl Maximums {
         }
     }
 }
+
+/// Represents relevant contents of .cargo_vcs_info.json file when uploaded from cargo
+/// or downloaded from crates.io
+#[derive(Debug, Deserialize, Eq, PartialEq)]
+pub struct CargoVcsInfo {
+    /// Path to the package within repo (empty string if root). / not \
+    #[serde(default)]
+    pub path_in_vcs: String,
+}
+
+impl CargoVcsInfo {
+    pub fn from_contents(contents: &str) -> serde_json::Result<Self> {
+        serde_json::from_str(contents)
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use super::CargoVcsInfo;
+
+    #[test]
+    fn test_cargo_vcs_info() {
+        assert_eq!(CargoVcsInfo::from_contents("").ok(), None);
+        assert_eq!(
+            CargoVcsInfo::from_contents("{}").unwrap(),
+            CargoVcsInfo {
+                path_in_vcs: "".into()
+            }
+        );
+        assert_eq!(
+            CargoVcsInfo::from_contents(r#"{"path_in_vcs": "hi"}"#).unwrap(),
+            CargoVcsInfo {
+                path_in_vcs: "hi".into()
+            }
+        );
+        assert_eq!(
+            CargoVcsInfo::from_contents(r#"{"path_in_vcs": "hi", "future": "field"}"#).unwrap(),
+            CargoVcsInfo {
+                path_in_vcs: "hi".into()
+            }
+        );
+    }
+}

src/worker/readmes.rs

@@ -14,11 +14,17 @@ pub fn render_and_upload_readme(
     text: String,
     readme_path: String,
     base_url: Option<String>,
+    pkg_path_in_vcs: Option<String>,
 ) -> Result<(), PerformError> {
     use crate::schema::*;
     use diesel::prelude::*;
 
-    let rendered = text_to_html(&text, &readme_path, base_url.as_deref());
+    let rendered = text_to_html(
+        &text,
+        &readme_path,
+        base_url.as_deref(),
+        pkg_path_in_vcs.as_deref(),
+    );
 
     conn.transaction(|| {
         Version::record_readme_rendering(version_id, conn)?;