Arrange that the --html output mode delivers a sensible error

[sgt/agedu] / trie.c

diff --git a/trie.c b/trie.c
index 51fba3e..ddadddb 100644 (file)
--- a/trie.c
+++ b/trie.c
@@ -218,7 +218,8 @@ static off_t triebuild_unwind(triebuild *tb, int targetdepth, int *outcount)
     while (depth > targetdepth) {
        int odepth = depth;
        while (depth > targetdepth &&
-              (depth-1 > tb->switchsize || tb->switches[depth-1].len == 0))
+              (depth-1 > tb->switchsize || !tb->switches ||
+               tb->switches[depth-1].len == 0))
            depth--;
        if (odepth > depth) {
            /*
@@ -628,6 +629,19 @@ triewalk *triewalk_new(const void *vt)
 
     return tw;
 }
+
+void triewalk_rebase(triewalk *tw, const void *t)
+{
+    ptrdiff_t diff = ((const unsigned char *)t - (const unsigned char *)(tw->t));
+    int i;
+
+    tw->t = t;
+
+    for (i = 0; i < tw->nswitches; i++)
+       tw->switches[i].sw = (const struct trie_switch *)
+           ((const unsigned char *)(tw->switches[i].sw) + diff);
+}
+
 const struct trie_file *triewalk_next(triewalk *tw, char *buf)
 {
     off_t off;