* configure.in: Invoke AM_LIB_DMALLOC.

* src/system.h: Use dmalloc.
* src/LR0.c: Be sure to have pointers initialized to NULL.
(allocate_itemsets): Allocate kernel_items only if needed.

configure

@@ -739,6 +739,8 @@ Optional Features:
 Optional Packages:
   --with-PACKAGE[=ARG]    use PACKAGE [ARG=yes]
   --without-PACKAGE       do not use PACKAGE (same as --with-PACKAGE=no)
+  --with-dmalloc          use dmalloc, as in
+                          http://www.dmalloc.com/dmalloc.tar.gz
   --with-libiconv-prefix=DIR  search for libiconv in DIR/include and DIR/lib
   --with-included-gettext use the GNU gettext library included here
 
@@ -6619,6 +6621,31 @@ _ACEOF
   fi
 fi
 
+echo "$as_me:$LINENO: checking if malloc debugging is wanted" >&5
+echo $ECHO_N "checking if malloc debugging is wanted... $ECHO_C" >&6
+
+# Check whether --with-dmalloc or --without-dmalloc was given.
+if test "${with_dmalloc+set}" = set; then
+  withval="$with_dmalloc"
+  if test "$withval" = yes; then
+  echo "$as_me:$LINENO: result: yes" >&5
+echo "${ECHO_T}yes" >&6
+
+cat >>confdefs.h <<\_ACEOF
+#define WITH_DMALLOC 1
+_ACEOF
+
+  LIBS="$LIBS -ldmalloc"
+  LDFLAGS="$LDFLAGS -g"
+else
+  echo "$as_me:$LINENO: result: no" >&5
+echo "${ECHO_T}no" >&6
+fi
+else
+  echo "$as_me:$LINENO: result: no" >&5
+echo "${ECHO_T}no" >&6
+fi;
+
 ALL_LINGUAS="de es et fr ja nl tr ru"
 # Make sure we can run config.sub.
 $ac_config_sub sun4 >/dev/null 2>&1 ||