common/hooks: fix python shebang rewrite for multi-versioned packages

common/hooks/pre-pkg/03-rewrite-python-shebang.sh

@@ -0,0 +1,36 @@
+# This hook executes the following tasks:
+#	- rewrites python shebangs with the corresponding python version
+
+hook() {
+	local pyver= shebang= warn=
+
+	case $pkgname in
+	python-*)
+		pyver=2.7;;
+	python3.4-*)
+		pyver=3.4;;
+	*)
+		for i in $python_versions; do
+			if [ "$pyver" ]; then
+				warn=1
+				break;
+			fi
+			pyver=$i
+		done
+		: ${pyver:=2.7}
+		;;
+	esac
+
+	shebang="#!/usr/bin/python$pyver"
+	find ${PKGDESTDIR} -type f -print0 | \
+		xargs -0 grep -H -b -m 1 "^#!.*\([[:space:]]\|/\)python\([[:space:]]\|$\)" -- | while IFS=: read -r f off _; do
+		[ "$off" -eq 0 ] || continue
+		if [ "$warn" ]; then
+			msg_warn "$pkgname: multiple python versions defined!"
+			msg_warn "$pkgname: using $pyver for shebang"
+			warn=
+		fi
+		echo "   Unversioned shebang replaced by '$shebang': ${f#$PKGDESTDIR}"
+		sed -i "1s@.*python@${shebang}@" -- "$f"
+	done
+}