preserve errno in OSError

3 files changed, 12 insertions, 8 deletions

diff --git a/py/objexcept.c b/py/objexcept.c
index c33ada0d6..8664060ec 100644
--- a/py/objexcept.c
+++ b/py/objexcept.c
@@ -112,14 +112,17 @@ void mp_obj_exception_print(const mp_print_t *print, mp_obj_t o_in, mp_print_kin
         if (o->args == NULL || o->args->len == 0) {
             mp_print_str(print, "");
             return;
-        } else if (o->args->len == 1) {
-            // try to provide a nice OSError error message
+        } else if (o->args->len <= 2) {
+            // try to provide a nice OSError error message; second arg might exist (e.g. filename).
             if (MP_OBJ_IS_SMALL_INT(o->args->items[0]) &&
                 mp_obj_is_subclass_fast(MP_OBJ_FROM_PTR(o->base.type), MP_OBJ_FROM_PTR(&mp_type_OSError))) {
                 char decompressed[50];
                 const char *msg = mp_common_errno_to_str(o->args->items[0], decompressed, sizeof(decompressed));
                 if (msg != NULL) {
                     mp_printf(print, "[Errno " INT_FMT "] %s", MP_OBJ_SMALL_INT_VALUE(o->args->items[0]), msg);
+                    if (o->args->len == 2) {
+                        mp_printf(print, ": '%s'", mp_obj_str_get_str(o->args->items[1]));
+                    }
                     return;
                 }
             }
diff --git a/py/runtime.c b/py/runtime.c
index cb174837c..c1c311ae4 100644
--- a/py/runtime.c
+++ b/py/runtime.c
@@ -1578,11 +1578,12 @@ NORETURN void mp_raise_OSError_msg(const compressed_string_t *msg) {
     mp_raise_msg(&mp_type_OSError, msg);
 }
 
-NORETURN void mp_raise_OSError_errno_str(int errno_, const char *str) {
-    char decompressed[50];
-    const char *errno_str = mp_common_errno_to_str(MP_OBJ_NEW_SMALL_INT(errno_),
-                                                   decompressed, sizeof(decompressed));
-    mp_raise_OSError_msg_varg(translate("[Errno %d] %s: %s"), errno_, errno_str, str);
+NORETURN void mp_raise_OSError_errno_str(int errno_, mp_obj_t str) {
+    mp_obj_t args[2] = {
+        MP_OBJ_NEW_SMALL_INT(errno_),
+        str,
+    };
+    nlr_raise(mp_obj_new_exception_args(&mp_type_OSError, 2, args));
 }
 
 NORETURN void mp_raise_OSError_msg_varg(const compressed_string_t *fmt, ...) {
diff --git a/py/runtime.h b/py/runtime.h
index 319de5bb9..f81103557 100644
--- a/py/runtime.h
+++ b/py/runtime.h
@@ -161,7 +161,7 @@ NORETURN void mp_raise_RuntimeError(const compressed_string_t *msg);
 NORETURN void mp_raise_ImportError(const compressed_string_t *msg);
 NORETURN void mp_raise_IndexError(const compressed_string_t *msg);
 NORETURN void mp_raise_OSError(int errno_);
-NORETURN void mp_raise_OSError_errno_str(int errno_, const char *str);
+NORETURN void mp_raise_OSError_errno_str(int errno_, mp_obj_t str);
 NORETURN void mp_raise_OSError_msg(const compressed_string_t *msg);
 NORETURN void mp_raise_OSError_msg_varg(const compressed_string_t *fmt, ...);
 NORETURN void mp_raise_NotImplementedError(const compressed_string_t *msg);