Avoid crashes in coding_inherit_eol_type

* src/coding.c (coding_inherit_eol_type): Check the validity of
the arguments.  Suggested by Andreas Schwab <schwab@linux-m68k.org>.
(Bug#21602)

1 files changed, 2 insertions, 0 deletions

diff --git a/src/coding.c b/src/coding.c
index 3fc6fb684c6..d2655310cd3 100644
--- a/src/coding.c
+++ b/src/coding.c
@@ -6004,6 +6004,7 @@ coding_inherit_eol_type (Lisp_Object coding_system, Lisp_Object parent)
 
   if (NILP (coding_system))
     coding_system = Qraw_text;
+  CHECK_CODING_SYSTEM (coding_system);
   spec = CODING_SYSTEM_SPEC (coding_system);
   eol_type = AREF (spec, 2);
   if (VECTORP (eol_type))
@@ -6014,6 +6015,7 @@ coding_inherit_eol_type (Lisp_Object coding_system, Lisp_Object parent)
         {
           Lisp_Object parent_spec;
 
+          CHECK_CODING_SYSTEM (parent);
           parent_spec = CODING_SYSTEM_SPEC (parent);
           parent_eol_type = AREF (parent_spec, 2);
           if (VECTORP (parent_eol_type))