diff --git a/src/applications/diffusion/conduit/DiffusionBranchQueryConduitAPIMethod.php b/src/applications/diffusion/conduit/DiffusionBranchQueryConduitAPIMethod.php
--- a/src/applications/diffusion/conduit/DiffusionBranchQueryConduitAPIMethod.php
+++ b/src/applications/diffusion/conduit/DiffusionBranchQueryConduitAPIMethod.php
@@ -30,7 +30,7 @@
     $repository = $drequest->getRepository();
 
     $contains = $request->getValue('contains');
-    if (strlen($contains)) {
+    if (phutil_nonempty_string($contains)) {
 
       // See PHI958 (and, earlier, PHI720). If "patterns" are provided, pass
       // them to "git branch ..." to let callers test for reachability from
diff --git a/src/applications/diffusion/controller/DiffusionBranchTableController.php b/src/applications/diffusion/controller/DiffusionBranchTableController.php
--- a/src/applications/diffusion/controller/DiffusionBranchTableController.php
+++ b/src/applications/diffusion/controller/DiffusionBranchTableController.php
@@ -26,7 +26,7 @@
     );
 
     $contains = $drequest->getSymbolicCommit();
-    if (strlen($contains)) {
+    if (phutil_nonempty_string($contains)) {
       $params['contains'] = $contains;
     }