Don't error on empty struct.

2 files changed, 7 insertions, 1 deletions

diff --git a/src/core/ffi.c b/src/core/ffi.c
index 9b149542..7cc1ae2f 100644
--- a/src/core/ffi.c
+++ b/src/core/ffi.c
@@ -424,6 +424,7 @@ static JanetFFIStruct *build_struct_type(int32_t argc, const Janet *argv) {
             st->size += (uint32_t) el_size;
         } else {
             if (el_align > st->align) st->align = (uint32_t) el_align;
+            if (el_align <= 0) el_align = 1;
             st->fields[i].offset = (uint32_t)(((st->size + el_align - 1) / el_align) * el_align);
             st->size = (uint32_t)(el_size + st->fields[i].offset);
         }
diff --git a/test/suite-ffi.janet b/test/suite-ffi.janet
index 0a810198..fb8d288c 100644
--- a/test/suite-ffi.janet
+++ b/test/suite-ffi.janet
@@ -52,5 +52,10 @@
   (assert (= 26 (ffi/size [:char :pack :int @[:char 21]]))
           "array struct size"))
 
-(end-suite)
+(compwhen has-ffi
+  (assert-no-error "bad struct issue #1512" (ffi/struct :void))
+  (def s (ffi/struct :void))
+  (assert (= 0 (ffi/size s)))
+  (assert (= 1 (ffi/align s))))
 
+(end-suite)