system: Add "--" after "-c" for sh (BZ #28519)

Prevent sh from interpreting a user string as shell options if it
starts with '-' or '+'.  Since the version of /bin/sh used for testing
system() is different from the full-fledged system /bin/sh add support
to it for handling "--" after "-c".  Add a testcase to ensure the
expected behavior.

Signed-off-by: Joe Simmons-Talbott <josimmon@redhat.com>
Reviewed-by: Adhemerval Zanella  <adhemerval.zanella@linaro.org>

1 files changed, 14 insertions, 0 deletions

diff --git a/stdlib/tst-system.c b/stdlib/tst-system.c
index 47a0afe6bf..3a55ec2791 100644
--- a/stdlib/tst-system.c
+++ b/stdlib/tst-system.c
@@ -148,6 +148,20 @@ do_test (void)
 
   {
     struct support_capture_subprocess result;
+    const char *cmd = "-echo";
+    result = support_capture_subprocess (call_system,
+					 &(struct args) { cmd, 127 });
+    support_capture_subprocess_check (&result, "system", 0, sc_allow_stderr |
+			sc_allow_stdout);
+    char *returnerr = xasprintf ("%s: execing -echo failed: "
+				 "No such file or directory",
+				 basename(_PATH_BSHELL));
+    TEST_COMPARE_STRING (result.err.buffer, returnerr);
+    free (returnerr);
+  }
+
+  {
+    struct support_capture_subprocess result;
     result = support_capture_subprocess (call_system,
 					 &(struct args) { "exit 1", 1 });
     support_capture_subprocess_check (&result, "system", 0, sc_allow_none);