Check for NULL constraint and raise exception if found.

User is not allowed to provide a NULL constraint to the various ARG
constructors. This patch makes sure the Constraint is not NULL before
dereferencing and raises a logic_error if it is NULL.

Also included the two new tests test88 and test89 in runtests script.

examples/Makefile.am

@@ -2,7 +2,7 @@
 noinst_PROGRAMS = test1 test2 test3 test4 test5 test6 test7 test8 test9 \
 			test10 test11 test12 test13 test14 test15 test16 \
 			test17 test18 test19 test20 test21 test22 test23 test24 \
-			test25 test26 test27
+			test25 test26 test27 test28
 
 test1_SOURCES = test1.cpp
 test2_SOURCES = test2.cpp
@@ -31,6 +31,7 @@ test24_SOURCES = test24.cpp
 test25_SOURCES = test25.cpp
 test26_SOURCES = test26.cpp
 test27_SOURCES = test27.cpp
+test28_SOURCES = test28.cpp
 
 AM_CPPFLAGS = -I$(top_srcdir)/include
 

examples/test28.cpp

@@ -0,0 +1,35 @@
+#include <iostream>
+
+#include "tclap/CmdLine.h"
+
+using namespace TCLAP;
+using namespace std;
+
+int main()
+{
+    try {
+	CmdLine cmd("test constraint bug");
+	ValueArg<int> arg("i","int", "tests int arg", false, 4711, NULL, cmd);
+	cout << "Expected exception" << endl;
+    } catch(std::logic_error &e) { /* expected */ }
+
+    try {
+	CmdLine cmd("test constraint bug");
+	ValueArg<int> arg1("i","int", "tests int arg", false, 4711, NULL, NULL);
+	cout << "Expected exception" << endl;
+    } catch(std::logic_error &e) { /* expected */ }
+
+    try {
+	CmdLine cmd("test constraint bug");
+	MultiArg<int> arg1("i","int", "tests int arg", false, NULL, NULL);
+	cout << "Expected exception" << endl;
+    } catch(std::logic_error &e) { /* expected */ }
+
+    try {
+	CmdLine cmd("test constraint bug");
+	MultiArg<int> arg1("i","int", "tests int arg", false, NULL, cmd);
+	cout << "Expected exception" << endl;
+    } catch(std::logic_error &e) { /* expected */ }
+
+    cout << "Passed" << endl;
+}

include/tclap/Constraint.h

@@ -28,6 +28,7 @@
 #include <iostream>
 #include <iomanip>
 #include <algorithm>
+#include <stdexcept>
 
 namespace TCLAP {
 
@@ -62,6 +63,12 @@ class Constraint
 		 * functions but without a virtual destructor.
 		 */
 		virtual ~Constraint() { ; }
+
+		static std::string shortID(Constraint<T> *constraint) {
+		  if (!constraint)
+		    throw std::logic_error("Cannot create a ValueArg with a NULL constraint");
+		  return constraint->shortID();
+		}
 };
 
 } //namespace TCLAP

include/tclap/MultiArg.h

@@ -276,7 +276,7 @@ MultiArg<T>::MultiArg(const std::string& flag,
                       Visitor* v)
 : Arg( flag, name, desc, req, true, v ),
   _values(std::vector<T>()),
-  _typeDesc( constraint->shortID() ),
+  _typeDesc( Constraint<T>::shortID(constraint) ),
   _constraint( constraint ),
   _allowMore(false)
 { 
@@ -293,7 +293,7 @@ MultiArg<T>::MultiArg(const std::string& flag,
                       Visitor* v)
 : Arg( flag, name, desc, req, true, v ),
   _values(std::vector<T>()),
-  _typeDesc( constraint->shortID() ),
+  _typeDesc( Constraint<T>::shortID(constraint) ),
   _constraint( constraint ),
   _allowMore(false)
 { 

include/tclap/ValueArg.h

@@ -302,7 +302,7 @@ ValueArg<T>::ValueArg(const std::string& flag,
   : Arg(flag, name, desc, req, true, v),
     _value( val ),
     _default( val ),
-    _typeDesc( constraint->shortID() ),
+    _typeDesc( Constraint<T>::shortID(constraint) ),
     _constraint( constraint )
 { }
 
@@ -318,7 +318,7 @@ ValueArg<T>::ValueArg(const std::string& flag,
   : Arg(flag, name, desc, req, true, v),
     _value( val ),
     _default( val ),
-    _typeDesc( constraint->shortID() ),  // TODO(macbishop): Will crash
+    _typeDesc( Constraint<T>::shortID(constraint) ),  // TODO(macbishop): Will crash
     // if constraint is NULL
     _constraint( constraint )
 { 

tests/runtests.sh

@@ -6,7 +6,7 @@ cd $DIR
 
 let "suc = 0"
 let "fail = 0"
-NUMTEST=87
+NUMTEST=89
 
 for (( tno = 1 ; $tno <= $NUMTEST ; tno = $tno + 1 )); do     
     ./testCheck.sh $tno

tests/test89.out

@@ -0,0 +1 @@
+Passed

tests/test89.sh

@@ -0,0 +1,9 @@
+#!/bin/bash
+
+../examples/test28 > tmp.out 2>&1
+
+if cmp -s tmp.out $srcdir/test89.out; then
+	exit 0
+else
+	exit 1
+fi