Fix kernel update check

update-notify

@@ -54,6 +54,19 @@ pending_version() {
     return 1
 }
 
+# Newest known version of $1: the pending version if an update is queued,
+# otherwise the installed version. Returns 1 if the package isn't installed.
+latest_version() {
+    local pkg=$1 ver
+    if ver=$(pending_version "$pkg"); then
+        printf '%s\n' "$ver"
+    elif ver=$(pacman -Q "$pkg" 2>/dev/null); then
+        printf '%s\n' "${ver#* }"
+    else
+        return 1
+    fi
+}
+
 # ---------------------------------------------------------------------------
 # Gather updates
 # ---------------------------------------------------------------------------
@@ -83,15 +96,20 @@ updates=$((arch_updates + aur_updates))
 for stock_pkg in "${!KERNELS[@]}"; do
     custom_pkg=${KERNELS[$stock_pkg]}
 
-    # Only relevant if the custom kernel is installed and has no pending update itself
-    if pacman -Q "$custom_pkg" >/dev/null 2>&1 && ! pending_version "$custom_pkg" >/dev/null; then
-        if stock_ver=$(pending_version "$stock_pkg"); then
-            notify_once "kernel-$stock_pkg" "Kernel update available: $stock_pkg" \
-                "Rebuild $custom_pkg ($stock_pkg $stock_ver)"
+    # Skip kernels where either package isn't installed
+    if ! stock_ver=$(latest_version "$stock_pkg") || ! custom_ver=$(latest_version "$custom_pkg"); then
+        clear_state "kernel-$stock_pkg"
         continue
     fi
-    fi
+
+    # Notify while the stock kernel is newer than the newest custom build
+    # (installed, or already built into your repo but not yet installed)
+    if (( $(vercmp "$stock_ver" "$custom_ver") > 0 )); then
+        notify_once "kernel-$stock_pkg" "Kernel update available: $stock_pkg" \
+            "Rebuild $custom_pkg ($stock_pkg $stock_ver)"
+    else
         clear_state "kernel-$stock_pkg"
+    fi
 done
 
 # ---------------------------------------------------------------------------