fix(pkgbuild): distro-specific functions must not be overwritten by base

When a PKGBUILD declares both 'prepare()' (priority 0, base) and
'prepare__ubuntu_jammy()' (priority 3, distro-specific), AddItem was
overwriting the higher-priority function with the base one whenever
the base directive was parsed after the distro variant — because
mapFunctions ran unconditionally even though the priority gate
already short-circuited variables/arrays for that case.

This broke distro-specific hooks any time the base function appeared
later in the file (the common pattern in PKGBUILDs that share a
helper '_prepare' and have one distro override calling it). The
symptom on Ubuntu jammy was the chrono-hours patch being silently
skipped because the jammy-specific prepare was clobbered by the
generic one.

Gate mapFunctions on priority >= oldPriority so distro/codename
variants survive a subsequent base assignment. Arrays still
accumulate (intentional, matches makepkg's source_<arch> behaviour);
this only changes function dispatch.

Author: M0Rf30

pkg/pkgbuild/pkgbuild.go

@@ -224,7 +224,15 @@ func (pkgBuild *PKGBUILD) AddItem(key string, data any) error {
 
 	pkgBuild.mapVariables(key, data)
 	pkgBuild.mapArrays(key, data, priority)
-	pkgBuild.mapFunctions(key, data)
+
+	// Functions, unlike arrays, do not accumulate across base/distro-specific
+	// variants — they replace. A previously stored higher-priority variant
+	// (e.g. prepare__ubuntu_jammy) must NOT be overwritten by a later base
+	// prepare() call. Only assign when this directive's priority is at least
+	// as high as the highest seen so far for this key.
+	if priority >= oldPriority {
+		pkgBuild.mapFunctions(key, data)
+	}
 
 	return nil
 }