From fa7bd04e27c35175c4b119648e766c32941911ff Mon Sep 17 00:00:00 2001
From: Raphael Fakhri <153192858+RaphaelFakhri@users.noreply.github.com>
Date: Tue, 3 Nov 2026 14:59:26 +0000
Subject: [PATCH] [go] Stop JobListParams.Where from mutating caller named args

When given more than one set of named arguments, JobListParams.Where
merged later sets into the first map it was passed, so the caller's map
picked up extra keys. Passing nil as the first set panicked with an
assignment to a nil map. Merge into a fresh map instead, the way
JobDeleteManyParams.Where already does.
---
 CHANGELOG.md            |  4 ++++
 job_list_params.go      | 11 ++++-------
 job_list_params_test.go | 25 +++++++++++++++++++++++++
 3 files changed, 33 insertions(+), 7 deletions(-)

diff --git a/CHANGELOG.md b/CHANGELOG.md
index 318cdea10..d234e683b 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -7,6 +7,10 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 ## [Unreleased]
 
+### Fixed
+
+- Fixed `JobListParams.Where` writing into the first `NamedArgs` it's given when merging multiple sets of named arguments, which could leak arguments into a map the caller reused for another query. It also no longer panics when the first set is `nil`. [PR #1575](https://github.com/riverqueue/river/pull/1575).
+
 ## [0.51.1] - 2026-11-05
 
 ### Fixed
diff --git a/job_list_params.go b/job_list_params.go
index bddd1be0c..a42bbe9c9 100644
--- a/job_list_params.go
+++ b/job_list_params.go
@@ -576,14 +576,11 @@ func (p *JobListParams) Where(sql string, namedArgsMany ...NamedArgs) *JobListPa
 	paramsCopy := p.copy()
 
 	var allNamedArgs NamedArgs
-	if len(namedArgsMany) > 0 {
-		for i, namedArgs := range namedArgsMany {
-			if i == 0 {
-				allNamedArgs = namedArgs
-			} else {
-				maps.Copy(allNamedArgs, namedArgs)
-			}
+	for _, namedArgs := range namedArgsMany {
+		if allNamedArgs == nil {
+			allNamedArgs = make(NamedArgs, len(namedArgs))
 		}
+		maps.Copy(allNamedArgs, namedArgs)
 	}
 
 	paramsCopy.where = append(paramsCopy.where, dblist.WherePredicate{NamedArgs: allNamedArgs, SQL: sql})
diff --git a/job_list_params_test.go b/job_list_params_test.go
index e964a5975..0e741ed39 100644
--- a/job_list_params_test.go
+++ b/job_list_params_test.go
@@ -636,3 +636,28 @@ func Test_JobListParams_toDBParamsWithoutFinalizedIndex(t *testing.T) {
 		})
 	}
 }
+
+func TestJobListParams_Where(t *testing.T) {
+	t.Parallel()
+
+	t.Run("MergesNamedArgsWithoutMutatingThem", func(t *testing.T) {
+		t.Parallel()
+
+		var (
+			namedArgs1 = NamedArgs{"a": 1, "b": 2}
+			namedArgs2 = NamedArgs{"b": 3}
+		)
+
+		params := NewJobListParams().Where("a = @a AND b = @b", namedArgs1, namedArgs2)
+		require.Equal(t, map[string]any{"a": 1, "b": 3}, params.where[0].NamedArgs)
+		require.Equal(t, NamedArgs{"a": 1, "b": 2}, namedArgs1)
+		require.Equal(t, NamedArgs{"b": 3}, namedArgs2)
+	})
+
+	t.Run("NilFirstNamedArgs", func(t *testing.T) {
+		t.Parallel()
+
+		params := NewJobListParams().Where("a = @a", nil, NamedArgs{"a": 1})
+		require.Equal(t, map[string]any{"a": 1}, params.where[0].NamedArgs)
+	})
+}