SERVER-37058: Update with numeric field names inside an array can cause validation to fail

1 files changed, 29 insertions, 0 deletions

diff --git a/jstests/core/update_numeric_field_name.js b/jstests/core/update_numeric_field_name.js
new file mode 100644
index 00000000000..bc165a7ca78
--- /dev/null
+++ b/jstests/core/update_numeric_field_name.js
@@ -0,0 +1,29 @@
+// Test that update operations correctly fail if they violate the "ambiguous field name in array"
+// constraint for indexes. This is designed to reproduce SERVER-37058.
+(function() {
+    "use strict";
+
+    const coll = db.coll;
+    coll.drop();
+
+    assert.writeOK(coll.insert({_id: 0, 'a': [{}]}));
+    assert.commandWorked(coll.createIndex({'a.0.c': 1}));
+
+    // Attempt to insert a field name '0'. The first '0' refers to the first element of the array
+    // 'a'.
+    assert.writeErrorWithCode(coll.update({_id: 0}, {$set: {'a.0.0': 1}}), 16746);
+
+    // Verify that the indexes were not affected.
+    let res = assert.commandWorked(coll.validate(true));
+    assert(res.valid, tojson(res));
+
+    assert.writeErrorWithCode(coll.update({_id: 0}, {$set: {'a.0.0.b': 1}}), 16746);
+    res = assert.commandWorked(coll.validate(true));
+    assert(res.valid, tojson(res));
+
+    // An update which does not violate the ambiguous field name in array constraint should succeed.
+    assert.writeOK(coll.update({_id: 0}, {$set: {'a.1.b.0.0': 1}}));
+
+    res = assert.commandWorked(coll.validate(true));
+    assert(res.valid, tojson(res));
+})();