Lua - Fix char pointers, wchar_t pointers and char arrays so that nil can be passed as a valid value

git-svn-id: https://swig.svn.sourceforge.net/svnroot/swig/trunk@11963 626c5289-ae23-0410-ae9c-e8d60b6d4f22

CHANGES.current

@@ -1,6 +1,10 @@
 Version 2.0.0 (in progress)
 ============================
 
+2010-04-02: wsfulton
+            [Lua] Fix char pointers, wchar_t pointers and char arrays so that nil can be passed as a
+            valid value. Bug reported by Gedalia Pasternak.
+
 2010-04-01: wsfulton
             Numerous subtle typemap matching rule fixes when using the default type. The typemap
             matching rules are to take a type and find the best default typemap (SWIGTYPE, SWIGTYPE* etc),

Examples/test-suite/char_strings.i

@@ -109,6 +109,12 @@ bool SetConstCharArrayStaticString(const char str[], unsigned int number) {
 char *CharPingPong(char *str) {
   return str;
 }
+char *CharArrayPingPong(char abcstr[]) {
+  return abcstr;
+}
+char *CharArrayDimsPingPong(char abcstr[16]) {
+  return abcstr;
+}
 
 // variables
 char *global_char = NULL;

Examples/test-suite/lua/char_strings_runme.lua

@@ -0,0 +1,12 @@
+require("import")	-- the import fn
+import("char_strings")	-- import code
+
+assert (char_strings.CharPingPong("hi there") == "hi there")
+assert (char_strings.CharPingPong(nil) == nil)
+
+assert (char_strings.CharArrayPingPong("hi there") == "hi there")
+assert (char_strings.CharArrayPingPong(nil) == nil)
+
+assert (char_strings.CharArrayDimsPingPong("hi there") == "hi there")
+assert (char_strings.CharArrayDimsPingPong(nil) == nil)
+

Lib/lua/luatypemaps.swg

@@ -90,10 +90,19 @@ temp=($basetype)lua_tonumber(L,$input); $1=&temp;%}
 %{  lua_pushboolean(L,(int)((*$1)!=0)); SWIG_arg++;%}
 
 // strings (char* and char[])
-%typemap(in,checkfn="lua_isstring") const char*, char*
+%fragment("SWIG_lua_isnilstring", "header") {
+  int SWIG_lua_isnilstring(lua_State *L, int idx) {
+    int ret = lua_isstring(L, idx);
+    if (!ret)
+     ret = lua_isnil(L, idx);
+    return ret;
+  }
+}
+
+%typemap(in,checkfn="SWIG_lua_isnilstring",fragment="SWIG_lua_isnilstring") const char*, char*
 %{$1 = ($ltype)lua_tostring(L, $input);%}
 
-%typemap(in,checkfn="lua_isstring") const char[ANY], char[ANY]
+%typemap(in,checkfn="SWIG_lua_isnilstring",fragment="SWIG_lua_isnilstring") const char[ANY], char[ANY]
 %{$1 = ($ltype)lua_tostring(L, $input);%}
 
 %typemap(out) const char*, char*
@@ -105,14 +114,14 @@ temp=($basetype)lua_tonumber(L,$input); $1=&temp;%}
 // char's
 // currently treating chars as small strings, not as numbers
 // (however signed & unsigned char's are numbers...)
-%typemap(in,checkfn="lua_isstring") char
+%typemap(in,checkfn="SWIG_lua_isnilstring",fragment="SWIG_lua_isnilstring") char
 %{$1 = (lua_tostring(L, $input))[0];%}
 
 %typemap(out) char
 %{  lua_pushfstring(L,"%c",$1); SWIG_arg++;%}
 
 // by const ref
-%typemap(in,checkfn="lua_isstring") const char& (char temp)
+%typemap(in,checkfn="SWIG_lua_isnilstring",fragment="SWIG_lua_isnilstring") const char& (char temp)
 %{temp = (lua_tostring(L, $input))[0]; $1=&temp;%}
 
 %typemap(out) const char&
@@ -288,12 +297,12 @@ parmeters match which function
 }
 
 // special check for a char (string of length 1)
-%typecheck(SWIG_TYPECHECK_CHAR) char, const char& {
-  $1 = lua_isstring(L,$input) && (lua_strlen(L,$input)==1);
+%typecheck(SWIG_TYPECHECK_CHAR,fragment="SWIG_lua_isnilstring") char, const char& {
+  $1 = SWIG_lua_isnilstring(L,$input) && (lua_strlen(L,$input)==1);
 }
 
-%typecheck(SWIG_TYPECHECK_STRING) char *, char[] {
-  $1 = lua_isstring(L,$input);
+%typecheck(SWIG_TYPECHECK_STRING,fragment="SWIG_lua_isnilstring") char *, char[] {
+  $1 = SWIG_lua_isnilstring(L,$input);
 }
 
 %typecheck(SWIG_TYPECHECK_POINTER) SWIGTYPE *, SWIGTYPE [] {

Lib/lua/wchar.i

@@ -28,13 +28,13 @@ wchar_t* str2wstr(const char* str, int len)
 }
 %}
 
-%typemap( in, checkfn="lua_isstring" ) wchar_t*
+%typemap(in, checkfn="SWIG_lua_isnilstring", fragment="SWIG_lua_isnilstring") wchar_t*
 %{
 $1 = str2wstr(lua_tostring( L, $input ),lua_strlen( L, $input ));
 if ($1==0) {lua_pushfstring(L,"Error in converting to wchar (arg %d)",$input);goto fail;}
 %}
 
-%typemap( freearg ) wchar_t*
+%typemap(freearg) wchar_t*
 %{
 free($1);
 %}