From fe23a14ebb692084cc1720a5f25157797d680c15 Mon Sep 17 00:00:00 2001
From: Michael Matz <matz@suse.de>
Date: Mon, 17 Jun 2019 18:52:49 +0200
Subject: [PATCH] Deal with more tentative definitions

see testcase.
---
 tccgen.c        |  1 +
 tests/tcctest.c | 10 ++++++++++
 2 files changed, 11 insertions(+)

diff --git a/tccgen.c b/tccgen.c
index 618e5ae..ca2a9a5 100644
--- a/tccgen.c
+++ b/tccgen.c
@@ -1005,6 +1005,7 @@ static Sym *external_sym(int v, CType *type, int r, AttributeDef *ad)
     Sym *s;
     s = sym_find(v);
     if (!s || (!IS_ASM_SYM(s) && !(s->type.t & VT_EXTERN)
+               && (!(type->t & VT_EXTERN) || s->sym_scope)
                && (s->type.t & VT_BTYPE) != VT_FUNC)) {
         if (s && !is_compatible_types(&s->type, type))
             tcc_error("conflicting types for '%s'", get_tok_str(s->v, NULL));
diff --git a/tests/tcctest.c b/tests/tcctest.c
index 77d7946..49bf863 100644
--- a/tests/tcctest.c
+++ b/tests/tcctest.c
@@ -816,6 +816,16 @@ void scope_test2()
     printf("exloc: %d\n", *st2_p);
 }
 
+/* C has tentative definition, and they may be repeated.  */
+extern int st_global1;
+int st_global1=42;
+extern int st_global1;
+int st_global1;
+extern int st_global2;
+int st_global2;
+extern int st_global2;
+int st_global2;
+
 void array_test()
 {
     int i, j, a[4];