Auto merge of #9188 - weihanglo:issue-9041, r=ehuss

Package ID specification urls must contain a host

Resolves #9041

Not sure which commit breaks this. Cargo shipped with rust 1.46 didn't unwrap on a `None` but 1.47 did. Even checkouted to 149022b (cargo of rust 1.46), it still unwrap unexpectedly.

So I ended up following the [Specification grammer](https://doc.rust-lang.org/cargo/reference/pkgid-spec.html#specification-grammar) to make sure there is a `host` in the pkgid urls.

<details>
<summary>See console output</summary>

cargo of rust 1.46
```console
$ cargo +1.46 -vV
cargo 1.46.0 (149022b 2020-07-17)
release: 1.46.0
commit-hash: 149022b
commit-date: 2020-07-17

$ cargo +1.46 pkgid /path
error: package ID specification `/path` matched no packages
```

cargo of rust 1.47

```console
$ cargo +1.47 -vV
cargo 1.47.0 (f3c7e06 2020-08-28)
release: 1.47.0
commit-hash: f3c7e06
commit-date: 2020-08-28

$ cargo +1.47 pkgid /path
thread 'main' panicked at 'called `Option::unwrap()` on a `None` value', src/tools/cargo/src/cargo/core/package_id_spec.rs:234:50
note: run with `RUST_BACKTRACE=1` environment variable to display a backtrace
```

cargo on commit 149022b

```console
$ git checkout 149022b
$ cargo run -- pkgid /path
   Compiling cargo-platform v0.1.1 ([..]/cargo/crates/cargo-platform)
   Compiling crates-io v0.31.1 ([..]/cargo/crates/crates-io)
   Compiling cargo v0.47.0 ([..]/cargo)
    Finished dev [unoptimized + debuginfo] target(s) in 22.90s
     Running `target/debug/cargo pkgid /path`
thread 'main' panicked at 'called `Option::unwrap()` on a `None` value', src/cargo/core/package_id_spec.rs:234:50
note: run with `RUST_BACKTRACE=1` environment variable to display a backtrace
```
</details>

src/cargo/core/package_id_spec.rs

@@ -38,27 +38,31 @@ impl PackageIdSpec {
     /// use cargo::core::PackageIdSpec;
     ///
     /// let specs = vec![
+    ///     "https://crates.io/foo",
     ///     "https://crates.io/foo#1.2.3",
     ///     "https://crates.io/foo#bar:1.2.3",
-    ///     "crates.io/foo",
-    ///     "crates.io/foo#1.2.3",
-    ///     "crates.io/foo#bar",
-    ///     "crates.io/foo#bar:1.2.3",
     ///     "foo",
     ///     "foo:1.2.3",
     /// ];
     /// for spec in specs {
     ///     assert!(PackageIdSpec::parse(spec).is_ok());
     /// }
     pub fn parse(spec: &str) -> CargoResult<PackageIdSpec> {
-        if spec.contains('/') {
+        if spec.contains("://") {
             if let Ok(url) = spec.into_url() {
                 return PackageIdSpec::from_url(url);
             }
-            if !spec.contains("://") {
-                if let Ok(url) = Url::parse(&format!("cargo://{}", spec)) {
-                    return PackageIdSpec::from_url(url);
-                }
+        } else if spec.contains('/') || spec.contains('\\') {
+            let abs = std::env::current_dir().unwrap_or_default().join(spec);
+            if abs.exists() {
+                let maybe_url = Url::from_file_path(abs)
+                    .map_or_else(|_| "a file:// URL".to_string(), |url| url.to_string());
+                bail!(
+                    "package ID specification `{}` looks like a file path, \
+                    maybe try {}",
+                    spec,
+                    maybe_url
+                );
             }
         }
         let mut parts = spec.splitn(2, ':');
@@ -80,8 +84,11 @@ impl PackageIdSpec {
     where
         I: IntoIterator<Item = PackageId>,
     {
-        let spec = PackageIdSpec::parse(spec)
-            .chain_err(|| anyhow::format_err!("invalid package ID specification: `{}`", spec))?;
+        let i: Vec<_> = i.into_iter().collect();
+        let spec = PackageIdSpec::parse(spec).chain_err(|| {
+            let suggestion = lev_distance::closest_msg(spec, i.iter(), |id| id.name().as_str());
+            anyhow::format_err!("invalid package ID specification: `{}`{}", spec, suggestion)
+        })?;
         spec.query(i)
     }
 
@@ -275,11 +282,7 @@ impl fmt::Display for PackageIdSpec {
         let mut printed_name = false;
         match self.url {
             Some(ref url) => {
-                if url.scheme() == "cargo" {
-                    write!(f, "{}{}", url.host().unwrap(), url.path())?;
-                } else {
-                    write!(f, "{}", url)?;
-                }
+                write!(f, "{}", url)?;
                 if url.path_segments().unwrap().next_back().unwrap() != &*self.name {
                     printed_name = true;
                     write!(f, "#{}", self.name)?;
@@ -333,51 +336,27 @@ mod tests {
         }
 
         ok(
-            "https://crates.io/foo#1.2.3",
-            PackageIdSpec {
-                name: InternedString::new("foo"),
-                version: Some("1.2.3".to_semver().unwrap()),
-                url: Some(Url::parse("https://crates.io/foo").unwrap()),
-            },
-        );
-        ok(
-            "https://crates.io/foo#bar:1.2.3",
-            PackageIdSpec {
-                name: InternedString::new("bar"),
-                version: Some("1.2.3".to_semver().unwrap()),
-                url: Some(Url::parse("https://crates.io/foo").unwrap()),
-            },
-        );
-        ok(
-            "crates.io/foo",
+            "https://crates.io/foo",
             PackageIdSpec {
                 name: InternedString::new("foo"),
                 version: None,
-                url: Some(Url::parse("cargo://crates.io/foo").unwrap()),
+                url: Some(Url::parse("https://crates.io/foo").unwrap()),
             },
         );
         ok(
-            "crates.io/foo#1.2.3",
+            "https://crates.io/foo#1.2.3",
             PackageIdSpec {
                 name: InternedString::new("foo"),
                 version: Some("1.2.3".to_semver().unwrap()),
-                url: Some(Url::parse("cargo://crates.io/foo").unwrap()),
-            },
-        );
-        ok(
-            "crates.io/foo#bar",
-            PackageIdSpec {
-                name: InternedString::new("bar"),
-                version: None,
-                url: Some(Url::parse("cargo://crates.io/foo").unwrap()),
+                url: Some(Url::parse("https://crates.io/foo").unwrap()),
             },
         );
         ok(
-            "crates.io/foo#bar:1.2.3",
+            "https://crates.io/foo#bar:1.2.3",
             PackageIdSpec {
                 name: InternedString::new("bar"),
                 version: Some("1.2.3".to_semver().unwrap()),
-                url: Some(Url::parse("cargo://crates.io/foo").unwrap()),
+                url: Some(Url::parse("https://crates.io/foo").unwrap()),
             },
         );
         ok(

src/doc/man/cargo-pkgid.md

@@ -81,5 +81,9 @@ Get the package ID for the given package instead of the current package.
 
        cargo pkgid https://github.com/rust-lang/crates.io-index#foo
 
+4. Retrieve package specification for `foo` from a local package:
+
+       cargo pkgid file:///path/to/local/package#foo
+
 ## SEE ALSO
 {{man "cargo" 1}}, {{man "cargo-generate-lockfile" 1}}, {{man "cargo-metadata" 1}}

src/doc/man/generated_txt/cargo-pkgid.txt

@@ -137,6 +137,10 @@ EXAMPLES
 
               cargo pkgid https://github.com/rust-lang/crates.io-index#foo
 
+       4. Retrieve package specification for foo from a local package:
+
+              cargo pkgid file:///path/to/local/package#foo
+
 SEE ALSO
        cargo(1), cargo-generate-lockfile(1), cargo-metadata(1)
 

src/doc/src/commands/cargo-pkgid.md

@@ -163,5 +163,9 @@ details on environment variables that Cargo reads.
 
        cargo pkgid https://github.com/rust-lang/crates.io-index#foo
 
+4. Retrieve package specification for `foo` from a local package:
+
+       cargo pkgid file:///path/to/local/package#foo
+
 ## SEE ALSO
 [cargo(1)](cargo.html), [cargo-generate-lockfile(1)](cargo-generate-lockfile.html), [cargo-metadata(1)](cargo-metadata.html)

src/etc/man/cargo-pkgid.1

@@ -207,5 +207,15 @@ cargo pkgid https://github.com/rust\-lang/crates.io\-index#foo
 .fi
 .RE
 .RE
+.sp
+.RS 4
+\h'-04' 4.\h'+01'Retrieve package specification for \fBfoo\fR from a local package:
+.sp
+.RS 4
+.nf
+cargo pkgid file:///path/to/local/package#foo
+.fi
+.RE
+.RE
 .SH "SEE ALSO"
 \fBcargo\fR(1), \fBcargo\-generate\-lockfile\fR(1), \fBcargo\-metadata\fR(1)

tests/testsuite/pkgid.rs

@@ -54,6 +54,7 @@ fn suggestion_bad_pkgid() {
             "#,
         )
         .file("src/lib.rs", "")
+        .file("cratesio", "")
         .build();
 
     p.cargo("generate-lockfile").run();
@@ -93,6 +94,34 @@ Did you mean one of these?
 
   two-ver:0.1.0
   two-ver:0.2.0
+",
+        )
+        .run();
+
+    // Bad file URL.
+    p.cargo("pkgid ./Cargo.toml")
+        .with_status(101)
+        .with_stderr(
+            "\
+error: invalid package ID specification: `./Cargo.toml`
+
+Caused by:
+  package ID specification `./Cargo.toml` looks like a file path, maybe try file://[..]/Cargo.toml
+",
+        )
+        .run();
+
+    // Bad file URL with simliar name.
+    p.cargo("pkgid './cratesio'")
+        .with_status(101)
+        .with_stderr(
+            "\
+error: invalid package ID specification: `./cratesio`
+
+<tab>Did you mean `crates-io`?
+
+Caused by:
+  package ID specification `./cratesio` looks like a file path, maybe try file://[..]/cratesio
 ",
         )
         .run();