aya: include NulError source in MapError::InvalidName

- The CString::new failure at MapData::create previously discarded
the underlying NulError. Marking it as #[source] so error reporters
can walk the chain.

This is a SemVer-minor change for callers that destructure
MapError::InvalidName { name } (now requires { name, source } or
{ name, .. }).

Author: surno

aya/src/maps/mod.rs

@@ -114,6 +114,9 @@ pub enum MapError {
     InvalidName {
         /// The map name
         name: String,
+        #[source]
+        /// The source error.
+        source: std::ffi::NulError,
     },
 
     /// Failed to create map
@@ -608,8 +611,10 @@ impl MapData {
         name: &str,
         btf_fd: Option<BorrowedFd<'_>>,
     ) -> Result<Self, MapError> {
-        let c_name = CString::new(name)
-            .map_err(|std::ffi::NulError { .. }| MapError::InvalidName { name: name.into() })?;
+        let c_name = CString::new(name).map_err(|source| MapError::InvalidName {
+            name: name.into(),
+            source,
+        })?;
 
         // BPF_MAP_TYPE_PERF_EVENT_ARRAY's max_entries should not exceed the number of
         // CPUs.

xtask/public-api/aya.txt

@@ -936,6 +936,7 @@ pub aya::maps::MapError::InvalidMapType
 pub aya::maps::MapError::InvalidMapType::map_type: u32
 pub aya::maps::MapError::InvalidName
 pub aya::maps::MapError::InvalidName::name: alloc::string::String
+pub aya::maps::MapError::InvalidName::source: alloc::ffi::c_str::NulError
 pub aya::maps::MapError::InvalidPinPath
 pub aya::maps::MapError::InvalidPinPath::path: std::path::PathBuf
 pub aya::maps::MapError::InvalidPinPath::source: alloc::ffi::c_str::NulError
@@ -1711,8 +1712,8 @@ pub fn aya::maps::loaded_maps() -> impl core::iter::traits::iterator::Iterator<I
 pub mod aya::pin
 pub enum aya::pin::PinError
 pub aya::pin::PinError::InvalidPinPath
-pub aya::pin::PinError::InvalidPinPath::error: alloc::ffi::c_str::NulError
 pub aya::pin::PinError::InvalidPinPath::path: std::path::PathBuf
+pub aya::pin::PinError::InvalidPinPath::source: alloc::ffi::c_str::NulError
 pub aya::pin::PinError::NoFd
 pub aya::pin::PinError::NoFd::name: alloc::string::String
 pub aya::pin::PinError::SyscallError(aya::sys::SyscallError)