Change the way symbols_list2.h is built to avoid some race conditions.

src/c/Makefile.in

@@ -113,11 +113,18 @@ $(DPP): $(srcdir)/dpp.c $(srcdir)/symbols_list2.h
 	if test -f ../CROSS-DPP; then touch dpp; else \
 	$(TRUE_CC) -I$(srcdir) -I@true_builddir@ -I./ $(srcdir)/dpp.c @CPPFLAGS@ @CFLAGS@ @ECL_CFLAGS@ -o $@ ; \
 	fi
+
+#
+# symbols_list2.h is built this way to allow for an atomic replacement of
+# the file. Otherwise we have problem when doing concurrent builds with
+# rsync updates of the source tree.
+#
 $(srcdir)/symbols_list2.h: $(srcdir)/symbols_list.h Makefile
 	cat $(srcdir)/symbols_list.h | \
 	sed -e 's%{\([A-Z ]*.*".*"\),[^,]*,[ ]*NULL,.*}%{\1,NULL}%g' \
 	    -e 's%{\([A-Z ]*.*".*"\),[^,]*,[ ]*\([^,]*\),.*}%{\1,"\2"}%g' \
-	    -e 's%{NULL.*%{NULL,NULL}};%' > $@
+	    -e 's%{NULL.*%{NULL,NULL}};%' > tmp.h
+	mv tmp.h $@
 
 #
 # GCC might break this code