[Go] Fixes for Go 1.6: avoid returning Go pointers from

directors that return string values; add a trailing 0 byte
when treating Go string as C char*.

Lib/go/go.swg

@@ -435,10 +435,22 @@
 
 %typemap(in)
 	char *, char[ANY], char[]
-%{ $1 = ($1_ltype)$input.p; %}
+%{
+  $1 = ($1_ltype)malloc($input.n + 1);
+  memcpy($1, $input.p, $input.n);
+  $1[$input.n] = '\0';
+%}
 
 %typemap(in) char *&
-%{ $1 = ($1_ltype)$input.p; %}
+%{
+  $1 = ($1_ltype)malloc($input.n + 1);
+  memcpy($1, $input.p, $input.n);
+  $1[$input.n] = '\0';
+%}
+
+%typemap(freearg)
+	char *, char *&, char[ANY], char[]
+%{ free($1); %}
 
 %typemap(out,fragment="AllocateString")
 	char *, char *&, char[ANY], char[]
@@ -460,7 +472,19 @@
   $result = swigCopyString($input)
 %}
 
-%typemap(directorout)
+%typemap(godirectorout)
+	char *, char *&, char[ANY], char[]
+%{
+  {
+    p := Swig_malloc(len($input) + 1)
+    s := (*[1<<30]byte)(unsafe.Pointer(p))[:len($input) + 1]
+    copy(s, $input)
+    s[len($input)] = 0
+    $result = *(*string)(unsafe.Pointer(&s))
+  }
+%}
+
+%typemap(directorout, warning=SWIGWARN_TYPEMAP_DIRECTOROUT_PTR_MSG)
 	char *, char *&, char[ANY], char[]
 %{ $result = ($1_ltype)$input.p; %}
 

Lib/go/goruntime.swg

@@ -8,6 +8,10 @@
 static void Swig_free(void* p) {
   free(p);
 }
+
+static void* Swig_malloc(int c) {
+  return malloc(c);
+}
 %}
 
 %insert(runtime) %{

Lib/go/std_string.i

@@ -24,8 +24,21 @@ class string;
 %typemap(in) string
 %{ $1.assign($input.p, $input.n); %}
 
+%typemap(godirectorout) string
+%{
+  {
+    p := Swig_malloc(len($input))
+    s := (*[1<<30]byte)(unsafe.Pointer(p))[:len($input)]
+    copy(s, $input)
+    $result = *(*string)(unsafe.Pointer(&s))
+  }
+%}
+
 %typemap(directorout) string
-%{ $result.assign($input.p, $input.n); %}
+%{
+  $result.assign($input.p, $input.n);
+  free($input.p);
+%}
 
 %typemap(out,fragment="AllocateString") string
 %{ $result = Swig_AllocateString($1.data(), $1.length()); %}
@@ -45,10 +58,21 @@ class string;
   $1 = &$1_str;
 %}
 
+%typemap(godirectorout) const string &
+%{
+  {
+    p := Swig_malloc(len($input))
+    s := (*[1<<30]byte)(unsafe.Pointer(p))[:len($input)]
+    copy(s, $input)
+    $result = *(*string)(unsafe.Pointer(&s))
+  }
+%}
+
 %typemap(directorout,warning=SWIGWARN_TYPEMAP_THREAD_UNSAFE_MSG) const string &
 %{
   static $*1_ltype $1_str;
   $1_str.assign($input.p, $input.n);
+  free($input.p);
   $result = &$1_str;
 %}