Auto merge of rust-lang#12146 - kristof-mattei:multiple-crate-versions-with-dashes, r=Manishearth

Fix [`multiple_crate_versions`] to correctly normalize package names to avoid missing the local one

Fixes rust-lang#12145

changelog: [`multiple_crate_versions`]: correctly normalize package name

Author: bors

clippy_lints/src/cargo/multiple_crate_versions.rs

@@ -16,7 +16,15 @@ pub(super) fn check(cx: &LateContext<'_>, metadata: &Metadata) {
 
     if let Some(resolve) = &metadata.resolve
         && let Some(local_id) = packages.iter().find_map(|p| {
-            if p.name == local_name.as_str() {
+            // p.name contains the original crate names with dashes intact
+            // local_name contains the crate name as a namespace, with the dashes converted to underscores
+            // the code below temporarily rectifies this discrepancy
+            if p.name
+                .as_bytes()
+                .iter()
+                .map(|b| if b == &b'-' { &b'_' } else { b })
+                .eq(local_name.as_str().as_bytes())
+            {
                 Some(&p.id)
             } else {
                 None

tests/ui-cargo/multiple_crate_versions/12145_with_dashes/Cargo.stderr

@@ -0,0 +1,6 @@
+error: multiple versions for dependency `winapi`: 0.2.8, 0.3.9
+  |
+  = note: `-D clippy::multiple-crate-versions` implied by `-D warnings`
+  = help: to override `-D warnings` add `#[allow(clippy::multiple_crate_versions)]`
+
+error: could not compile `multiple-crate-versions` (bin "multiple-crate-versions") due to 1 previous error

tests/ui-cargo/multiple_crate_versions/12145_with_dashes/Cargo.toml

@@ -0,0 +1,14 @@
+# Should not lint for dev or build dependencies. See issue 5041.
+
+[package]
+# purposefully separated by - instead of _
+name = "multiple-crate-versions"
+version = "0.1.0"
+publish = false
+
+[workspace]
+
+# One of the versions of winapi is only a dev dependency: allowed
+[dependencies]
+winapi = "0.2"
+ansi_term = "=0.11.0"

tests/ui-cargo/multiple_crate_versions/12145_with_dashes/src/main.rs

@@ -0,0 +1,3 @@
+#![warn(clippy::multiple_crate_versions)]
+
+fn main() {}