core/load-fragment: avoid allocating 0 bytes when given an invalid command

With a command line like "@/something" we would allocate an array with
0 elements. Avoid that, and add a test too.

1 files changed, 2 insertions, 1 deletions

diff --git a/src/core/load-fragment.c b/src/core/load-fragment.c
index eea415883b..242b684ddf 100644
--- a/src/core/load-fragment.c
+++ b/src/core/load-fragment.c
@@ -589,7 +589,8 @@ int config_parse_exec(const char *unit,
                 }
 
         found:
-                n = new(char*, k + !separate_argv0);
+                /* If seperate_argv0, we'll move first element to path variable */
+                n = new(char*, MAX(k + !separate_argv0, 1u));
                 if (!n)
                         return log_oom();