Fix potential null pointer dereferences

4 files changed, 14 insertions, 5 deletions

diff --git a/.clang-tidy b/.clang-tidy
index 17b9b27..84771ad 100644
--- a/.clang-tidy
+++ b/.clang-tidy
@@ -9,7 +9,6 @@ Checks: >
   -cert-err34-c,
   -cert-msc30-c,
   -cert-msc50-cpp,
-  -clang-analyzer-core.NullDereference,
   -cppcoreguidelines-init-variables,
   -google-readability-casting,
   -hicpp-multiway-paths-covered,
diff --git a/wscript b/wscript
index a69ffb8..858bd51 100644
--- a/wscript
+++ b/wscript
@@ -59,7 +59,6 @@ def configure(conf):
                 '-Wno-cast-align',
                 '-Wno-conversion',
                 '-Wno-inline',
-                '-Wno-null-dereference',
                 '-Wno-padded',
                 '-Wno-suggest-attribute=const',
                 '-Wno-suggest-attribute=pure',
diff --git a/zix/btree.c b/zix/btree.c
index dc8f32b..55d6613 100644
--- a/zix/btree.c
+++ b/zix/btree.c
@@ -593,8 +593,10 @@ zix_btree_remove(ZixBTree* const      t,
 					                            n->children[1]->n_vals};
 
 					n = zix_btree_merge(t, n, 0);
-					ti->stack[ti->level].node = n;
-					ti->stack[ti->level].index = counts[i];
+					if (ti) {
+						ti->stack[ti->level].node = n;
+						ti->stack[ti->level].index = counts[i];
+					}
 				} else {
 					// Both child's siblings are minimal, merge them
 					if (i < n->n_vals) {
diff --git a/zix/trie.c b/zix/trie.c
index 5083f3b..29f31d1 100644
--- a/zix/trie.c
+++ b/zix/trie.c
@@ -215,7 +215,11 @@ trie_insert_tail(ZixTrieNode**  n_ptr,
 	while (first[0]) {
 		assert(zix_trie_node_check(*n_ptr));
 
-		c               = realloc_node(NULL, 1);
+		c = realloc_node(NULL, 1);
+		if (!c) {
+			return NULL;
+		}
+
 		c->str          = NULL;
 		c->num_children = 0;
 
@@ -225,6 +229,11 @@ trie_insert_tail(ZixTrieNode**  n_ptr,
 
 		++first;
 	}
+
+	if (!c) {
+		return NULL;
+	}
+
 	c->num_children = 0;
 	c->str = str;
 	assert(zix_trie_node_check(c));