check iteration on empty vectors

3 files changed, 14 insertions, 0 deletions

diff --git a/include/conts/spvec.h b/include/conts/spvec.h
index 4fffb4a..d557fa8 100644
--- a/include/conts/spvec.h
+++ b/include/conts/spvec.h
@@ -193,6 +193,13 @@ static inline void SPVEC(shrink)(struct SPVEC_STRUCT *v, size_t n)
 
 static inline SPVEC_ITER SPVEC(begin)(struct SPVEC_STRUCT *v)
 {
+	if (v->n == 0) {
+		return (SPVEC_ITER) {
+			.i = 0,
+			.v = NULL
+		};
+	}
+
 	return (SPVEC_ITER){
 		.i = 0,
 		.v = SPVEC(at)(v, 0)
diff --git a/tests/spvec.c b/tests/spvec.c
index aa9b96c..b46bd88 100644
--- a/tests/spvec.c
+++ b/tests/spvec.c
@@ -21,6 +21,9 @@ int main()
 	atexit(covsrv_destroy);
 #endif
 	struct ints ints = ints_create();
+	foreach(ints, iter, &ints) {
+		assert(false && "iterating empty spvec");
+	}
 
 	/* ensure stability before we do anything else */
 	assert(ints_reserve(&ints, 1));
diff --git a/tests/vec.c b/tests/vec.c
index 1ed5f72..af36b5c 100644
--- a/tests/vec.c
+++ b/tests/vec.c
@@ -28,6 +28,10 @@ int main()
 #endif
 
 	struct ints ints = ints_create(0);
+	foreach(ints, iter, &ints) {
+		assert(false && "iterating empty vec");
+	}
+
 	for (int i = 0; i < 1000000; ++i) {
 		if (!ints_append(&ints, i)) {
 			fprintf(stderr, "failed appending %d to vec\n", i);