Handle missing WATCHDOG_PID in watchdog_enabled

CHANGELOG.md

@@ -6,6 +6,10 @@
 
  - (breaking) the `unset_env` parameters were split off into separate unsafe functions
  - (breaking) `watchdog_enabled` now returns `Option<Duration>`
+ - the MSRV is now defined as 1.82
+
+ ### Fixed
+ - fixed `watchdog_enabled` to handle missing `WATCHDOG_PID`
 
 ## [0.4.5] - 2025-01-18
 
@@ -35,42 +39,42 @@
 
 ### Changed
 
-- added `watchdog_enabled` (similar to [`sd_watchdog_enabled`](https://www.freedesktop.org/software/systemd/man/sd_watchdog_enabled.html))
+ - added `watchdog_enabled` (similar to [`sd_watchdog_enabled`](https://www.freedesktop.org/software/systemd/man/sd_watchdog_enabled.html))
 
 ## [0.4.0] - 2022-01-12
 
 ### Changed
 
-- (breaking) `NotifyState::Status`, `NotifyState::BusError` and `NotifyState::Custom` now contain a `&str` instead of a `String`
-- the crate is now using the 2021 edition
+ - (breaking) `NotifyState::Status`, `NotifyState::BusError` and `NotifyState::Custom` now contain a `&str` instead of a `String`
+ - the crate is now using the 2021 edition
 
 ## [0.3.0] - 2021-02-25
 
 ### Changed
 
-- (breaking) `listen_fds` now returns an iterator over `RawFd` values
-- (breaking) `SD_LISTEN_FDS_START` is gone
+ - (breaking) `listen_fds` now returns an iterator over `RawFd` values
+ - (breaking) `SD_LISTEN_FDS_START` is gone
 
 ## [0.2.0] - 2021-02-18
 
 ### Changed
 
-- (breaking) changed the `NotifyState::MainPid` and `NotifyState::Error` data from `i32` to `u32`
-- (breaking) changed `listen_fds` to return `Result<u32>` instead of `Result<i32>`
+ - (breaking) changed the `NotifyState::MainPid` and `NotifyState::Error` data from `i32` to `u32`
+ - (breaking) changed `listen_fds` to return `Result<u32>` instead of `Result<i32>`
 
 ### Fixed
 
-- fixed `Display` implementation for `NotifyState::WatchdogUsec` and `NotifyState::ExtendTimeoutUsec`
-- removed a stray debug print
+ - fixed `Display` implementation for `NotifyState::WatchdogUsec` and `NotifyState::ExtendTimeoutUsec`
+ - removed a stray debug print
 
 ## [0.1.1] - 2019-10-20
 
 ### Added
 
-- `listen_fds` function for file descriptor retrieval when using socket activation
+ - `listen_fds` function for file descriptor retrieval when using socket activation
 
 ## [0.1.0] - 2019-09-22
 
 ### Added
 
-- initial release
+ - initial release

Cargo.toml

@@ -2,6 +2,7 @@
 name = "sd-notify"
 version = "0.5.0"
 edition = "2021"
+rust-version = "1.82"
 description = "Lightweight crate for systemd service state notifications"
 readme = "README.md"
 keywords = ["systemd", "sd_notify"]

src/lib.rs

@@ -486,13 +486,8 @@ pub fn watchdog_enabled() -> Option<Duration> {
     let p = env::var(WATCHDOG_PID)
         .ok()
         .and_then(|s| u32::from_str(&s).ok());
-
-    match (s, p) {
-        (Some(usec_val), Some(pid)) if pid == process::id() => {
-            Some(Duration::from_micros(usec_val))
-        }
-        _ => None,
-    }
+    s.filter(|_| p.is_none_or(|pid| pid == process::id()))
+        .map(Duration::from_micros)
 }
 
 /// Asks the service manager for enabled watchdog.

tests/watchdog_enabled.rs

@@ -35,13 +35,28 @@ fn watchdog_enabled() {
     assert!(env::var_os("WATCHDOG_USEC").is_none());
     assert!(env::var_os("WATCHDOG_PID").is_none());
 
-    // no usec, no pip no unset env
+    // valid usec, no pid
+    unsafe {
+        env::set_var("WATCHDOG_USEC", "10");
+    }
+
+    unsafe {
+        assert_eq!(
+            sd_notify::watchdog_enabled_and_unset_env(),
+            Some(Duration::from_micros(10))
+        );
+    }
+
+    assert!(env::var_os("WATCHDOG_USEC").is_none());
+    assert!(env::var_os("WATCHDOG_PID").is_none());
+
+    // no usec, no pid, no unset env
     assert_eq!(sd_notify::watchdog_enabled(), None);
 
     assert!(env::var_os("WATCHDOG_USEC").is_none());
     assert!(env::var_os("WATCHDOG_PID").is_none());
 
-    // valid pip
+    // valid pid
     unsafe {
         env::set_var("WATCHDOG_USEC", "5");
         env::set_var("WATCHDOG_PID", process::id().to_string());