Fix crash on duplicated protected body.

src/parse.c

@@ -7841,6 +7841,11 @@ static tree_t p_protected_type_body(ident_t id)
    if (decl != NULL) {
       switch (tree_kind(decl)) {
       case T_PROT_BODY:   // Duplicate body will trigger an error later
+         if (!tree_has_primary(decl)) {
+            assert(error_count() > 0); // Fallout from previous error, ignore
+            decl = NULL;
+            break;
+         }
          decl = tree_primary(decl);
          // Fall-through
       case T_PROT_DECL:

test/parse/protected3.vhd

@@ -4,3 +4,11 @@ package fred4 is
     impure function hi_there return is_empty; -- error
   end protected;
 end package fred4;
+
+--------------------------------------------------------------------------------
+
+package pkg is
+  type SharedCounter is protected body -- first definition, but incomplete
+  type SharedCounter is protected body -- duplicated definition
+  end protected body;
+end package;

test/test_parse.c

@@ -6979,11 +6979,14 @@ START_TEST(test_protected3)
 
    const error_t expect[] = {
       {  4, "type mark does not denote a type or a subtype" },
+      { 11, "no visible declaration for SHAREDCOUNTER" },
+      { 14, "unexpected package while parsing protected type body, "
+            "expecting protected" },
       { -1, NULL }
    };
    expect_errors(expect);
 
-   parse_and_check(T_PACKAGE);
+   parse_and_check(T_PACKAGE, T_PACKAGE);
 
    fail_unless(parse() == NULL);