tests: add some tests for unit_name_is_valid() and related functions

I was surprised to see that foo@bar@bar.service is a valid unit
name. Apparently it is according to current code and docs.

diff --git a/src/basic/unit-name.c b/src/basic/unit-name.c
index 85f06126c7c2f4e026e50344f0d357d0fd924b5f..113d9bb10dab9d2d61b0b454ae34dc4c19720e49 100644 (file)
--- a/src/basic/unit-name.c
+++ b/src/basic/unit-name.c
@@ -716,7 +716,7 @@ int slice_build_parent_slice(const char *slice, char **ret) {
 }
 #endif // 0
 
-int slice_build_subslice(const char *slice, const char*name, char **ret) {
+int slice_build_subslice(const char *slice, const char *name, char **ret) {
         char *subslice;
 
         assert(slice);