#1381 Crash having named structs within anonymous union

[Torben]

Code to reproduce:

// swig.exe -c++ -java test.i
%module Test
%inline %{
    union //Union1
    {
       struct Struct1
       {
          int i1;
       };
       struct Struct2
       {
          int i2;
       };
    };
%}

Produces the following exception:
0xC0000005: Access violation reading location 0x00000000

Call stack:
msvcrt.dll!_strlen() + 0x26 bytes
swig.exe!0041a392()

Versions:
SWIG Version 3.0.2
Compiled with i586-mingw32msvc-g++ [i586-pc-mingw32msvc]
Configured options: +pcre

Windows 7 Professional SP1 [Version 6.1.7601]

The crash can be prevented by:
- naming the union
- removing the names from the structs
- running without the –c++ option

[Olly Betts]

Reproducible with current git master on Linux.

This patch at least prevents the crash:

diff --git a/Source/Modules/lang.cxx b/Source/Modules/lang.cxx
index eb61752b..f7f6aea1 100644
--- a/Source/Modules/lang.cxx
+++ b/Source/Modules/lang.cxx
@@ -2466,8 +2466,11 @@ int Language::classDeclaration(Node *n) {
     cplus_mode = PUBLIC;
   }
   for (; outerClass; outerClass = Getattr(outerClass, "nested:outer")) {
-    Push(ClassPrefix, "_");
-    Push(ClassPrefix, Getattr(outerClass, "sym:name"));
+    String *outer_symname = Getattr(outerClass, "sym:name");
+    if (outer_symname) {
+      Push(ClassPrefix, "_");
+      Push(ClassPrefix, outer_symname);
+    }
   }
   EnumClassPrefix = Copy(ClassPrefix);
   if (strip) {

However with that applied the example gives some strange warnings about constructors and destructors which aren't explicitly in the example interface file:

$ ../preinst-swig -c++ -java test.i
test.i:7: Warning 504: Function Struct1::Struct1() must have a return type. Ignored.
test.i:7: Warning 521: Illegal destructor name Struct1::~Struct1(). Ignored.
test.i:11: Warning 504: Function Struct2::Struct2() must have a return type. Ignored.
test.i:11: Warning 521: Illegal destructor name Struct2::~Struct2(). Ignored.