Fix handling of missing SASL libs when relying on default value for with-mongodb-sasl

Author: alcaeus

config.w32

@@ -232,27 +232,33 @@ if (PHP_MONGODB != "no") {
     WARNING("mongodb libopenssl support not enabled, libs not found");
   }
 
-  if (PHP_MONGODB_SASL != "no" &&
-      CHECK_LIB("libsasl.lib", "mongodb", PHP_MONGODB) &&
-      CHECK_HEADER_ADD_INCLUDE("sasl/sasl.h", "CFLAGS_MONGODB")) {
-
-    // TODO 3.0: Remove warning on "yes" as it implies "sspi"
-    if (PHP_MONGODB_SASL == "yes") {
-      WARNING("Cyrus SASL support for Windows was removed. Falling back to SSPI; use '--with-mongodb-sasl=sspi' to avoid this warning.");
-    }
-
-    if (PHP_MONGODB_SASL == "yes" || PHP_MONGODB_SASL == "sspi") {
-      mongoc_opts.MONGOC_ENABLE_SASL = 1;
-      mongoc_opts.MONGOC_ENABLE_SASL_SSPI = 1;
+  has_sasl_libs = CHECK_LIB("libsasl.lib", "mongodb", PHP_MONGODB) &&
+    CHECK_HEADER_ADD_INCLUDE("sasl/sasl.h", "CFLAGS_MONGODB");
+  if (PHP_MONGODB_SASL != "no") {
+    if (has_sasl_libs) {
+      // TODO 3.0: Remove warning on "yes" as it implies "sspi"
+      if (PHP_MONGODB_SASL == "yes") {
+        WARNING("Cyrus SASL support for Windows was removed. Falling back to SSPI; use '--with-mongodb-sasl=sspi' to avoid this warning.");
+        PHP_MONGODB_SASL = "sspi";
+      }
+
+      if (PHP_MONGODB_SASL == "sspi") {
+        mongoc_opts.MONGOC_ENABLE_SASL = 1;
+        mongoc_opts.MONGOC_ENABLE_SASL_SSPI = 1;
+      } else {
+        ERROR("MongoDB SASL support not enabled, unknown value for --with-mongodb-sasl: " + PHP_MONGODB_SASL);
+      }
+
+      if (CHECK_FUNC_IN_HEADER("sasl/sasl.h", "sasl_client_done")) {
+        mongoc_opts.MONGOC_HAVE_SASL_CLIENT_DONE = 1;
+      }
+    } else if (PHP_MONGODB_SASL != "yes") {
+      // If the user explicitly requested SASL support, we error out if the
+      // necessary libraries are not found.
+      ERROR("MongoDB SASL support not enabled, libs not found");
     } else {
-      ERROR("MongoDB SASL support not enabled, unknown value for --with-mongodb-sasl: " + PHP_MONGODB_SASL);
-    }
-
-    if (CHECK_FUNC_IN_HEADER("sasl/sasl.h", "sasl_client_done")) {
-      mongoc_opts.MONGOC_HAVE_SASL_CLIENT_DONE = 1;
+      WARNING("MongoDB SASL support not enabled, libs not found");
     }
-  } else if (PHP_MONGODB_SASL != "no") {
-    ERROR("MongoDB SASL support not enabled, libs not found");
   }
 
   if (PHP_MONGODB_CLIENT_SIDE_ENCRYPTION != "no" && mongoc_ssl_found) {