From ff0d8f91724850f5157bd2f55a1408773bb7d4f8 Mon Sep 17 00:00:00 2001
From: Tim Jenness <tjenness@lsst.org>
Date: Thu, 5 Sep 2024 13:44:58 -0700
Subject: [PATCH] Change command-line to convert limit=0 to limit=None for API
 usage

---
 python/lsst/daf/butler/script/queryDatasets.py | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/python/lsst/daf/butler/script/queryDatasets.py b/python/lsst/daf/butler/script/queryDatasets.py
index 7a1f147f8d..082853a6c3 100644
--- a/python/lsst/daf/butler/script/queryDatasets.py
+++ b/python/lsst/daf/butler/script/queryDatasets.py
@@ -273,8 +273,9 @@ def getDatasets(self) -> Iterator[DatasetRef]:
             kwargs: dict[str, Any] = {}
             if self._where:
                 kwargs["where"] = self._where
-            if not unlimited:
-                kwargs["limit"] = limit
+            # API uses 0 to mean "check query but return nothing" and None
+            # to mean "unlimited".
+            kwargs["limit"] = None if unlimited else limit
             _LOG.debug("Querying dataset type %s with %s", dt, kwargs)
             results = self.butler.query_datasets(
                 dt,