registry: avoid negating INT32_MIN

diff --git a/src/registry.c b/src/registry.c
index f7eca9ab1d26721afb60561e092e1111944086f4..c4e625231a1c190d0b9514bf2d79f9684b0b579b 100644 (file)
--- a/src/registry.c
+++ b/src/registry.c
@@ -193,16 +193,16 @@ get_cell_pointer(const struct regf *regf, le32 offset, size_t wanted_size)
        u32 total = le32_to_cpu(regf->total_hbin_size);
        u32 offs = le32_to_cpu(offset);
        const struct cell *cell;
-       s32 actual_size;
+       u32 actual_size;
 
        if ((offs > total) || (offs & 7) || (wanted_size > total - offs))
                return NULL;
 
        cell = (const struct cell *)&regf->hbin_area[offs];
-       actual_size = le32_to_cpu(cell->size);
-       if (actual_size >= 0) /* Cell not in use?  */
+       actual_size = -le32_to_cpu(cell->size);
+       if (actual_size > INT32_MAX) /* Cell unused, or size was INT32_MIN?  */
                return NULL;
-       if (wanted_size > -actual_size) /* Cell too small?  */
+       if (wanted_size > actual_size) /* Cell too small?  */
                return NULL;
        return cell;
 }