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, 6 insertions, 1 deletions

diff --git a/support/shell-container.c b/support/shell-container.c
index b1f9e793c1..28437e4206 100644
--- a/support/shell-container.c
+++ b/support/shell-container.c
@@ -455,7 +455,12 @@ main (int argc, const char **argv)
     dprintf (stderr, "  argv[%d] is `%s'\n", i, argv[i]);
 
   if (strcmp (argv[1], "-c") == 0)
-    run_command_string (argv[2], argv+3);
+    {
+      if (strcmp (argv[2], "--") == 0)
+		run_command_string (argv[3], argv+4);
+      else
+		run_command_string (argv[2], argv+3);
+    }
   else
     run_script (argv[1], argv+2);