@@ -10,7 +10,7 @@ INSTALL_DATA=${INSTALL} -m 644

 all: fzy fzytest

-fzytest: fzytest.o match.o

+fzytest: fzytest.o match.o choices.o

 	$(CC) $(CFLAGS) $(CCFLAGS) -o $@ $^

 test: fzytest

@@ -80,10 +80,12 @@ double choices_getscore(choices_t *c, size_t n){

 }

 void choices_prev(choices_t *c){

-	c->selection = (c->selection + c->available - 1) % c->available;

+	if(c->available)

+		c->selection = (c->selection + c->available - 1) % c->available;

 }

 void choices_next(choices_t *c){

-	c->selection = (c->selection + 1) % c->available;

+	if(c->available)

+		c->selection = (c->selection + 1) % c->available;

 }

@@ -1,5 +1,7 @@

 #include <stdio.h>

+

 #include "match.h"

+#include "choices.h"

 int testsrun = 0, testsfailed = 0, assertionsrun = 0;

@@ -109,6 +111,23 @@ int test_positions_exact(){

 	return 0;

 }

+int test_empty_choices(){

+	choices_t choices;

+	choices_init(&choices);

+	assert(choices.size == 0);

+	assert(choices.available == 0);

+	assert(choices.selection == 0);

+

+	choices_prev(&choices);

+	assert(choices.selection == 0);

+

+	choices_next(&choices);

+	assert(choices.selection == 0);

+

+	choices_free(&choices);

+	return 0;

+}

+

 void summary(){

 	printf("%i tests, %i assertions, %i failures\n", testsrun, assertionsrun, testsfailed);

 }

@@ -125,6 +144,8 @@ int main(int argc, char *argv[]){

 	runtest(test_positions_4);

 	runtest(test_positions_exact);

+	runtest(test_empty_choices);

+

 	summary();

 	/* exit 0 if all tests pass */