Change the length of strings created from fixed-size buffers.

Use the usual C rule for NUL-terminated strings instead of discarding all the
trailing NUL characters.

This was unexpected (as buffers in C code are not necessarily always padded
with NULs to their full length) and also inconsistent among languages as this
was only done for those of them using typemaps/strings.swg but not for C# or
Java, for example, which terminated the string at the first NUL even before
this change.

Notice that this patch couldn't use strlen() or wcslen() with possibly not
NUL-terminated strings, so we had to add [our own equivalents of] strnlen()
and wcsnlen() and use them instead. This required adding yet another parameter
to string typemap macros, so update the example using them accordingly too.

Examples/perl5/xmlstring/xmlstring.i

@@ -93,6 +93,17 @@ SWIG_FromXMLChPtrAndSize(const XMLCh* input, size_t size)
 }
 }
 
+%fragment("SWIG_XMLStringNLen","header") {
+size_t
+SWIG_XMLStringNLen(const XMLCh* s, size_t maxlen)
+{
+  const XMLCh *p;
+  for (p = s; maxlen-- && *p; p++)
+    ;
+  return p - s;
+}
+}
+
 %init {
   if (!SWIG_UTF8Transcoder()) {
     croak("ERROR: XML::Xerces: INIT: Could not create UTF-8 transcoder");
@@ -106,6 +117,7 @@ SWIG_FromXMLChPtrAndSize(const XMLCh* input, size_t size)
 		 SWIG_AsXMLChPtrAndSize, 
 		 SWIG_FromXMLChPtrAndSize,
 		 XERCES_CPP_NAMESPACE::XMLString::stringLen,
+		 SWIG_XMLStringNLen,
 		 "<XMLCh.h>", INT_MIN, INT_MAX);
 
 

Examples/test-suite/perl5/primitive_types_runme.pl

@@ -166,7 +166,7 @@ $t->{var_paramd} = $primitive_types::sct_paramd;
 $t->{var_paramc} = $primitive_types::sct_paramc;
 ok($t->v_check(), 'v_check');
 
-is($primitive_types::def_namet, "ho\0la", "namet");
+is($primitive_types::def_namet, "hola", "namet");
 $t->{var_namet} = $primitive_types::def_namet;
 is($t->{var_namet}, $primitive_types::def_namet, "namet");
 

Examples/test-suite/primitive_types.i

@@ -185,7 +185,7 @@
   char* const def_pchar = (char *const)"hello";
   const char* const def_pcharc = "hija";
 
-  const namet def_namet = {'h','o',0, 'l','a'};
+  const namet def_namet = {'h','o','l','a', 0};
 
   extern namet gbl_namet;
 

Examples/test-suite/python/primitive_types_runme.py

@@ -165,7 +165,7 @@ t.var_paramc = sct_paramc
 t.v_check()
 
 # this value contains a '0' char!
-if def_namet != 'ho\0la':
+if def_namet != 'hola':
   print "bad namet", def_namet
   raise RuntimeError