[Minor] Add NULL check in hash_html_features for safety

Add explicit NULL check for html_content pointer in hash_html_features()
to prevent potential undefined behavior. While features are initialized by
the HTML parser and checked in rspamd_shingles_from_html(), this provides
an additional safety layer against unexpected function calls.

diff --git a/src/libutil/shingles_html.cxx b/src/libutil/shingles_html.cxx
index 6a6e6cd806d34a99ed39a1683467e07a2295c876..33dc44ca9176af2a9fd77f2396c8d9469d47bbaa 100644 (file)
--- a/src/libutil/shingles_html.cxx
+++ b/src/libutil/shingles_html.cxx
@@ -287,6 +287,11 @@ hash_html_features(html_content *hc, const unsigned char key[16])
        unsigned char digest[rspamd_cryptobox_HASHBYTES];
        uint64_t result;
 
+       if (!hc) {
+               /* Return zero hash for NULL input */
+               return 0;
+       }
+
        rspamd_cryptobox_hash_init(&st, key, 16);
 
        /* Bucket numeric features for stability */
@@ -295,6 +300,7 @@ hash_html_features(html_content *hc, const unsigned char key[16])
        static const int depth_buckets[] = {5, 10, 15, 20, 30};
        static const int images_buckets[] = {1, 5, 10, 20, 50};
 
+       /* Access features with safe defaults (0 if uninitialized) */
        uint8_t tags_bucket = bucket_value(hc->features.tags_count, tags_buckets, G_N_ELEMENTS(tags_buckets));
        uint8_t links_bucket = bucket_value(hc->features.links.total_links, links_buckets, G_N_ELEMENTS(links_buckets));
        uint8_t depth_bucket = bucket_value(hc->features.max_dom_depth, depth_buckets, G_N_ELEMENTS(depth_buckets));