prevent division by zero for gradient with no points and add test

[libsvgtiny.git] / src / svgtiny_gradient.c

diff --git a/src/svgtiny_gradient.c b/src/svgtiny_gradient.c
index f5984ea313eeb5e4958653b2d3921a120a64a245..c36df3207675aed084a8357706ef06efdf55d0bb 100644 (file)
--- a/src/svgtiny_gradient.c
+++ b/src/svgtiny_gradient.c
@@ -410,8 +410,7 @@ svgtiny_code svgtiny_add_path_linear_gradient(float *p, unsigned int n,
        /* r, r0, r1 are distance along gradient vector */
        gradient_norm_squared = gradient_dx * gradient_dx +
                                      gradient_dy * gradient_dy;
-       pts = svgtiny_list_create(
-                       sizeof (struct grad_point));
+       pts = svgtiny_list_create(sizeof (struct grad_point));
        if (!pts)
                return svgtiny_OUT_OF_MEMORY;
        for (j = 0; j != n; ) {
@@ -540,6 +539,13 @@ svgtiny_code svgtiny_add_path_linear_gradient(float *p, unsigned int n,
                        svgtiny_list_size(pts), min_pt, min_r);
        #endif
 
+        /* There must be at least a single point for the gradient */
+        if (svgtiny_list_size(pts) == 0) {
+            svgtiny_list_free(pts);
+
+            return svgtiny_OK;
+        }
+        
        /* render triangles */
        stop_count = state->linear_gradient_stop_count;
        assert(2 <= stop_count);