nsp: stop sending nullptr strings with PR_EMS_AB_PROXY_ADDRESSES

References: GXH-173
Fixes: gromox-3.0-66-g133ddb459

Author: jengelh

exch/nsp/nsp_interface.cpp

@@ -468,7 +468,7 @@ static ec_error_t nsp_interface_fetch_property(const ab_tree::ab_node &node,
 		size_t i = 1;
 		for (const auto &a : alias_list) {
 			temp_len = a.size() + 6;
-			char *z = pprop->value.string_array.ppstr[i] = ndr_stack_anew<char>(NDR_STACK_OUT, temp_len);
+			char *z = pprop->value.string_array.ppstr[i++] = ndr_stack_anew<char>(NDR_STACK_OUT, temp_len);
 			if (z == nullptr)
 				return ecServerOOM;
 			snprintf(z, temp_len, "SMTP:%s", a.c_str());

lib/mapi/ext_buffer.cpp

@@ -2527,6 +2527,11 @@ pack_result EXT_PUSH::p_str_a(const STRING_ARRAY &r)
 	TRY(p_uint32(r.count));
 	for (size_t i = 0; i < r.count; ++i) {
 		if (m_flags & EXT_FLAG_ABK) {
+			/*
+			 * Ironically, Outlook's NSP handler eventually crashes
+			 * when it encounters a null string so idk why MS felt
+			 * a need to allow sending nullptr.
+			 */
 			if (r.ppstr[i] == nullptr) {
 				TRY(p_uint8(0));
 				continue;