FLTK: fix file save as handling

Author: chrisws

src/platform/fltk/HelpWidget.cxx

@@ -437,6 +437,11 @@ struct BrNode : public BaseNode {
 struct AnchorNode : public BaseNode {
   AnchorNode(Attributes &p) :
     BaseNode(),
+    x1(0),
+    x2(0),
+    y1(0),
+    y2(0),
+    lineHeight(0),
     wrapxy(0),
     pushed(0) {
     p.getName(name);

src/ui/strlib.cpp

@@ -23,7 +23,7 @@ String::String(const char *s) {
 }
 
 String::String(const String &s) {
-  _buffer = strdup(s._buffer);
+  _buffer = s._buffer == NULL ? NULL : strdup(s._buffer);
 }
 
 String::String(const char *s, int len) : _buffer(NULL) {