shrpx: Fix bug in building certificate lookup tree

src/shrpx_ssl.cc

@@ -587,7 +587,11 @@ void cert_lookup_tree_add_cert(CertLookupTree *lt, CertNode *node,
           cn->str[i] == hostname[j]; --i, --j);
     if(i == cn->last) {
       if(j == -1) {
+        if(cn->ssl_ctx) {
           // same hostname, we don't overwrite exiting ssl_ctx
+        } else {
+          cn->ssl_ctx = ssl_ctx;
+        }
       } else {
         // The existing hostname is a suffix of this hostname.
         // Continue matching at potion j.

src/shrpx_ssl_test.cc

@@ -96,9 +96,10 @@ void test_shrpx_ssl_create_lookup_tree(void)
   }
 
   SSL_CTX *ctxs2[] = {SSL_CTX_new(TLSv1_method()),
+                      SSL_CTX_new(TLSv1_method()),
                       SSL_CTX_new(TLSv1_method()),
                       SSL_CTX_new(TLSv1_method())};
-  const char *names[] = { "rab", "zab", "zzub" };
+  const char *names[] = { "rab", "zab", "zzub", "ab" };
   num = sizeof(ctxs2)/sizeof(ctxs2[0]);
   tree = ssl::cert_lookup_tree_new();
   for(int i = 0; i < num; ++i) {