Use null instead of empty string to represent missing checksum

crates/cargo-test-support/src/publish.rs

@@ -161,7 +161,7 @@ pub(crate) fn create_index_line(
     name: serde_json::Value,
     vers: &str,
     deps: Vec<serde_json::Value>,
-    cksum: &str,
+    cksum: Option<&str>,
     features: crate::registry::FeatureMap,
     yanked: bool,
     links: Option<String>,

crates/cargo-test-support/src/registry.rs

@@ -809,7 +809,7 @@ impl HttpServer {
                 serde_json::json!(new_crate.name),
                 &new_crate.vers,
                 deps,
-                &cksum(file),
+                Some(&cksum(file)),
                 new_crate.features,
                 false,
                 new_crate.links,
@@ -1080,9 +1080,9 @@ impl Package {
             .collect::<Vec<_>>();
         let cksum = if self.generate_checksum {
             let c = t!(fs::read(&self.archive_dst()));
-            cksum(&c)
+            Some(cksum(&c))
         } else {
-            String::new()
+            None
         };
         let name = if self.invalid_json {
             serde_json::json!(1)
@@ -1093,7 +1093,7 @@ impl Package {
             name,
             &self.vers,
             deps,
-            &cksum,
+            cksum.as_deref(),
             self.features.clone(),
             self.yanked,
             self.links.clone(),
@@ -1108,7 +1108,7 @@ impl Package {
 
         write_to_index(&registry_path, &self.name, line, self.local);
 
-        cksum
+        cksum.unwrap_or_else(String::new)
     }
 
     fn make_archive(&self) {

src/cargo/core/resolver/mod.rs

@@ -147,10 +147,7 @@ pub fn resolve(
 
     let mut cksums = HashMap::new();
     for (summary, _) in cx.activations.values() {
-        let cksum = summary
-            .checksum()
-            .map(|s| s.to_string())
-            .filter(|s| !s.is_empty());
+        let cksum = summary.checksum().map(|s| s.to_string());
         cksums.insert(summary.package_id(), cksum);
     }
     let graph = cx.graph();

src/cargo/sources/registry/http_remote.rs

@@ -8,7 +8,7 @@ use crate::sources::registry::download;
 use crate::sources::registry::MaybeLock;
 use crate::sources::registry::{LoadResponse, RegistryConfig, RegistryData};
 use crate::util::errors::CargoResult;
-use crate::util::{Config, Filesystem, IntoUrl, Progress, ProgressStyle};
+use crate::util::{internal, Config, Filesystem, IntoUrl, Progress, ProgressStyle};
 use anyhow::Context;
 use cargo_util::paths;
 use curl::easy::{HttpVersion, List};
@@ -543,7 +543,8 @@ impl<'cfg> RegistryData for HttpRegistry<'cfg> {
         self.requested_update = true;
     }
 
-    fn download(&mut self, pkg: PackageId, checksum: &str) -> CargoResult<MaybeLock> {
+    fn download(&mut self, pkg: PackageId, checksum: Option<&str>) -> CargoResult<MaybeLock> {
+        let checksum = checksum.ok_or_else(|| internal(format!("no hash listed for {}", pkg)))?;
         let registry_config = loop {
             match self.config()? {
                 Poll::Pending => self.block_until_ready()?,

src/cargo/sources/registry/index.rs

@@ -265,15 +265,18 @@ impl<'cfg> RegistryIndex<'cfg> {
     }
 
     /// Returns the hash listed for a specified `PackageId`.
-    pub fn hash(&mut self, pkg: PackageId, load: &mut dyn RegistryData) -> Poll<CargoResult<&str>> {
+    pub fn hash(
+        &mut self,
+        pkg: PackageId,
+        load: &mut dyn RegistryData,
+    ) -> Poll<CargoResult<Option<&str>>> {
         let req = OptVersionReq::exact(pkg.version());
         let summary = self.summaries(pkg.name(), &req, load)?;
         let summary = ready!(summary).next();
         Poll::Ready(Ok(summary
             .ok_or_else(|| internal(format!("no hash listed for {}", pkg)))?
             .summary
-            .checksum()
-            .ok_or_else(|| internal(format!("no hash listed for {}", pkg)))?))
+            .checksum()))
     }
 
     /// Load a list of summaries for `name` package in this registry which
@@ -855,7 +858,7 @@ impl IndexSummary {
             }
         }
         let mut summary = Summary::new(config, pkgid, deps, &features, links)?;
-        summary.set_checksum(cksum);
+        cksum.map(|cksum| summary.set_checksum(cksum));
         Ok(IndexSummary {
             summary,
             yanked: yanked.unwrap_or(false),

src/cargo/sources/registry/local.rs

@@ -108,7 +108,7 @@ impl<'cfg> RegistryData for LocalRegistry<'cfg> {
         self.updated
     }
 
-    fn download(&mut self, pkg: PackageId, checksum: &str) -> CargoResult<MaybeLock> {
+    fn download(&mut self, pkg: PackageId, checksum: Option<&str>) -> CargoResult<MaybeLock> {
         let crate_file = format!("{}-{}.crate", pkg.name(), pkg.version());
 
         // Note that the usage of `into_path_unlocked` here is because the local
@@ -129,8 +129,10 @@ impl<'cfg> RegistryData for LocalRegistry<'cfg> {
         // We don't actually need to download anything per-se, we just need to
         // verify the checksum matches the .crate file itself.
         let actual = Sha256::new().update_file(&crate_file)?.finish_hex();
-        if actual != checksum && !checksum.is_empty() {
-            anyhow::bail!("failed to verify the checksum of `{}`", pkg)
+        if let Some(checksum) = checksum {
+            if actual != checksum {
+                anyhow::bail!("failed to verify the checksum of `{}`", pkg)
+            }
         }
 
         crate_file.seek(SeekFrom::Start(0))?;

src/cargo/sources/registry/mod.rs

@@ -179,6 +179,7 @@ use crate::core::source::MaybePackage;
 use crate::core::{Package, PackageId, QueryKind, Source, SourceId, Summary};
 use crate::sources::PathSource;
 use crate::util::hex;
+use crate::util::internal;
 use crate::util::interning::InternedString;
 use crate::util::into_url::IntoUrl;
 use crate::util::network::PollExt;
@@ -271,7 +272,7 @@ pub struct RegistryPackage<'a> {
     /// will fail to load due to not being able to parse the new syntax, even
     /// with a `Cargo.lock` file.
     features2: Option<BTreeMap<InternedString, Vec<InternedString>>>,
-    cksum: String,
+    cksum: Option<String>,
     /// If `true`, Cargo will skip this version when resolving.
     ///
     /// This was added in 2014. Everything in the crates.io index has this set
@@ -486,7 +487,7 @@ pub trait RegistryData {
     /// `finish_download`. For already downloaded `.crate` files, it does not
     /// validate the checksum, assuming the filesystem does not suffer from
     /// corruption or manipulation.
-    fn download(&mut self, pkg: PackageId, checksum: &str) -> CargoResult<MaybeLock>;
+    fn download(&mut self, pkg: PackageId, checksum: Option<&str>) -> CargoResult<MaybeLock>;
 
     /// Finish a download by saving a `.crate` file to disk.
     ///
@@ -794,7 +795,9 @@ impl<'cfg> Source for RegistrySource<'cfg> {
                 Poll::Pending => self.block_until_ready()?,
                 Poll::Ready(hash) => break hash,
             }
-        };
+        }
+        .ok_or_else(|| internal(format!("no hash listed for {}", package)))?;
+
         let file = self.ops.finish_download(package, hash, &data)?;
         self.get_pkg(package, &file)
     }

src/cargo/sources/registry/remote.rs

@@ -5,7 +5,7 @@ use crate::sources::registry::MaybeLock;
 use crate::sources::registry::{LoadResponse, RegistryConfig, RegistryData};
 use crate::util::errors::CargoResult;
 use crate::util::interning::InternedString;
-use crate::util::{Config, Filesystem};
+use crate::util::{internal, Config, Filesystem};
 use anyhow::Context as _;
 use cargo_util::paths;
 use lazycell::LazyCell;
@@ -310,7 +310,8 @@ impl<'cfg> RegistryData for RemoteRegistry<'cfg> {
         self.updated
     }
 
-    fn download(&mut self, pkg: PackageId, checksum: &str) -> CargoResult<MaybeLock> {
+    fn download(&mut self, pkg: PackageId, checksum: Option<&str>) -> CargoResult<MaybeLock> {
+        let checksum = checksum.ok_or_else(|| internal(format!("no hash listed for {}", pkg)))?;
         let registry_config = loop {
             match self.config()? {
                 Poll::Pending => self.block_until_ready()?,