5 files changed, 49 insertions, 16 deletions
diff --git a/include/mruby.h b/include/mruby.h
index b112b081c..e058d409f 100644
--- a/include/mruby.h
+++ b/include/mruby.h
@@ -156,6 +156,7 @@ void mrb_undef_class_method(mrb_state*, struct RClass*, const char*);
 mrb_value mrb_instance_new(mrb_state *mrb, mrb_value cv);
 struct RClass * mrb_class_new(mrb_state *mrb, struct RClass *super);
 struct RClass * mrb_module_new(mrb_state *mrb);
+int mrb_class_defined(mrb_state *mrb, const char *name);
 struct RClass * mrb_class_get(mrb_state *mrb, const char *name);
 struct RClass * mrb_class_obj_get(mrb_state *mrb, const char *name);
 
diff --git a/src/class.c b/src/class.c
index 0ba702919..a00000375 100644
--- a/src/class.c
+++ b/src/class.c
@@ -203,6 +203,12 @@ mrb_vm_define_class(mrb_state *mrb, mrb_value outer, mrb_value super, mrb_sym id
   return c;
 }
 
+int
+mrb_class_defined(mrb_state *mrb, const char *name)
+{
+  return mrb_const_defined(mrb, mrb_obj_value(mrb->object_class), mrb_intern(mrb, name));
+}
+
 static struct RClass *
 class_from_sym(mrb_state *mrb, struct RClass *klass, mrb_sym id)
 {
diff --git a/src/error.c b/src/error.c
index 421321c3d..6bd891768 100644
--- a/src/error.c
+++ b/src/error.c
@@ -5,6 +5,7 @@
 */
 
 #include "mruby.h"
+#include <errno.h>
 #include <stdarg.h>
 #include <setjmp.h>
 #include <string.h>
@@ -401,7 +402,20 @@ mrb_make_exception(mrb_state *mrb, int argc, mrb_value *argv)
 void
 mrb_sys_fail(mrb_state *mrb, const char *mesg)
 {
-  mrb_raise(mrb, E_RUNTIME_ERROR, mesg);
+  struct RClass *sce;
+  mrb_int no;
+
+  no = (mrb_int)errno;
+  if (mrb_class_defined(mrb, "SystemCallError")) {
+    sce = mrb_class_get(mrb, "SystemCallError");
+    if (mesg != NULL) {
+      mrb_funcall(mrb, mrb_obj_value(sce), "_sys_fail", 2, mrb_fixnum_value(no), mrb_str_new_cstr(mrb, mesg));
+    } else {
+      mrb_funcall(mrb, mrb_obj_value(sce), "_sys_fail", 1, mrb_fixnum_value(no));
+    }
+  } else {
+    mrb_raise(mrb, E_RUNTIME_ERROR, mesg);
+  }
 }
 
 void
diff --git a/src/state.c b/src/state.c
index b6805a4a4..efb6d66b1 100644
--- a/src/state.c
+++ b/src/state.c
@@ -53,6 +53,7 @@ mrb_alloca(mrb_state *mrb, size_t size)
   struct alloca_header *p;
 
   p = (struct alloca_header*) mrb_malloc(mrb, sizeof(struct alloca_header)+size);
+  if (p == NULL) return NULL;
   p->next = mrb->mems;
   mrb->mems = p;
   return (void*)p->buf;
@@ -61,9 +62,12 @@ mrb_alloca(mrb_state *mrb, size_t size)
 static void
 mrb_alloca_free(mrb_state *mrb)
 {
-  struct alloca_header *p = mrb->mems;
+  struct alloca_header *p;
   struct alloca_header *tmp;
 
+  if (mrb == NULL) return NULL;
+  p = mrb->mems;
+
   while (p) {
     tmp = p;
     p = p->next;
diff --git a/test/driver.c b/test/driver.c
index eda82a7f2..4a7a7b25e 100644
--- a/test/driver.c
+++ b/test/driver.c
@@ -36,13 +36,31 @@ check_error(mrb_state *mrb)
   return mrb_fixnum_p(ko_test) && mrb_fixnum(ko_test) == 0 && mrb_fixnum_p(kill_test) && mrb_fixnum(kill_test) == 0;
 }
 
+static int
+eval_test(mrb_state *mrb)
+{
+  mrb_value return_value;
+  const char *prog = "report()";
+
+  /* evaluate the test */
+  return_value = mrb_load_string(mrb, prog);
+  /* did an exception occur? */
+  if (mrb->exc) {
+    mrb_p(mrb, return_value);
+    mrb->exc = 0;
+    return EXIT_FAILURE;
+  }
+  else if (!check_error(mrb)) {
+    return EXIT_FAILURE;
+  }
+  return EXIT_SUCCESS;
+}
+
 int
 main(int argc, char **argv)
 {
   mrb_state *mrb;
-  mrb_value return_value;
-  const char *prog = "report()";
-  int ret = EXIT_SUCCESS;
+  int ret;
 
   print_hint();
 
@@ -59,17 +77,7 @@ main(int argc, char **argv)
   }
 
   mrb_init_mrbtest(mrb);
-  /* evaluate the test */
-  return_value = mrb_load_string(mrb, prog);
-  /* did an exception occur? */
-  if (mrb->exc) {
-    mrb_p(mrb, return_value);
-    mrb->exc = 0;
-    ret = EXIT_FAILURE;
-  }
-  else if (!check_error(mrb)) {
-    ret = EXIT_FAILURE;
-  }
+  ret = eval_test(mrb);
   mrb_close(mrb);
 
   return ret;