X-Git-Url: https://git.distorted.org.uk/~mdw/sgt/agedu/blobdiff_plain/7e25423cd18ab429b13c6e2ea920d9c44c0f263c..HEAD:/index.c

diff --git a/index.c b/index.c
index 1cdb2ea..f4b9801 100644
--- a/index.c
+++ b/index.c
@@ -69,11 +69,11 @@ struct indexbuild {
 };
 
 #define ELEMENT(t,offset) \
-    ((offset) ? (struct trie_file *)((char *)(t) + (offset)) : NULL)
+    ((struct trie_file *) ((offset) ? ((char *)(t) + (offset)) : NULL))
 #define NODE(t,offset) \
-    ((offset) ? (struct avlnode *)((char *)(t) + (offset)) : NULL)
+    ((struct avlnode *) ((offset) ? ((char *)(t) + (offset)) : NULL))
 #define OFFSET(t,node) \
-    ((node) ? (off_t)((const char *)node - (const char *)t) : 0)
+    ((node) ? (off_t)((const char *)node - (const char *)t) : (off_t)0)
 #define MAXDEPTH(node) ((node) ? (node)->maxdepth : 0)
 
 indexbuild *indexbuild_new(void *t, off_t startoff, int nodecount,
@@ -283,6 +283,19 @@ void indexbuild_free(indexbuild *ib)
     sfree(ib);
 }
 
+int index_has_root(const void *t, int n)
+{
+    const off_t *roots;
+
+    roots = (const off_t *)((const char *)t + trie_get_index_offset(t));
+
+    if (n == 0)
+	return 1;
+    if (n < 0 || n >= trie_count(t) || !roots[n-1])
+	return 0;
+    return 1;
+}
+
 unsigned long long index_query(const void *t, int n, unsigned long long at)
 {
     const off_t *roots;