fix: correct escaped single quote parsing in Enum type strings

lib/column/enum.go

@@ -75,7 +75,7 @@ func extractEnumNamedValues(chType Type) (typ string, values []string, indexes [
 	var skippedValueTokens []int
 	var indexFound bool
 	var valueFound bool
-	var valueIndex = 0
+	valueIndex := 0
 
 	for c := 0; c < len(src); c++ {
 		token := src[c]
@@ -144,14 +144,15 @@ func extractEnumNamedValues(chType Type) (typ string, values []string, indexes [
 			}
 
 			foundName := src[foundValueOffset : foundValueOffset+foundValueLen]
-			for _, skipped := range skippedValueTokens {
-				foundName = append(foundName[:skipped], foundName[skipped+1:]...)
+			for i, skipped := range skippedValueTokens {
+				foundName = append(foundName[:skipped-i], foundName[skipped-i+1:]...)
 			}
 
 			indexes = append(indexes, valueIndex)
 			values = append(values, string(foundName))
 			indexFound = false
 			valueFound = false
+			skippedValueTokens = skippedValueTokens[:0]
 		}
 	}
 

lib/column/enum_test.go

@@ -159,6 +159,40 @@ func TestExtractEnumNamedValues(t *testing.T) {
 				0:  "b",
 			},
 		},
+		{
+			name:         "Enum8 with escaped quote in multiple values",
+			chType:       `Enum8('a\'b'=1,'c\'d'=2)`,
+			expectedType: "Enum8",
+			expectedValues: map[int]string{
+				1: "a'b",
+				2: "c'd",
+			},
+		},
+		{
+			name:         "Enum8 with multiple escaped quotes in one value",
+			chType:       `Enum8('a\'b\'c'=1)`,
+			expectedType: "Enum8",
+			expectedValues: map[int]string{
+				1: "a'b'c",
+			},
+		},
+		{
+			name:         "Enum16 with escaped quote in multiple values",
+			chType:       `Enum16('a\'b'=1,'c\'d'=2)`,
+			expectedType: "Enum16",
+			expectedValues: map[int]string{
+				1: "a'b",
+				2: "c'd",
+			},
+		},
+		{
+			name:         "Enum16 with multiple escaped quotes in one value",
+			chType:       `Enum16('a\'b\'c'=1)`,
+			expectedType: "Enum16",
+			expectedValues: map[int]string{
+				1: "a'b'c",
+			},
+		},
 	}
 	for _, tt := range tests {
 		t.Run(tt.name, func(t *testing.T) {

tests/issues/1839_test.go

@@ -0,0 +1,91 @@
+package issues
+
+import (
+	"context"
+	"testing"
+
+	"github.com/stretchr/testify/require"
+
+	"github.com/ClickHouse/clickhouse-go/v2"
+	clickhouse_tests "github.com/ClickHouse/clickhouse-go/v2/tests"
+)
+
+func Test1839(t *testing.T) {
+	testEnv, err := clickhouse_tests.GetTestEnvironment("issues")
+	require.NoError(t, err)
+	conn, err := clickhouse_tests.TestClientWithDefaultSettings(testEnv)
+	require.NoError(t, err)
+	t.Cleanup(func() { conn.Close() })
+
+	require.NoError(t, conn.Exec(t.Context(), `
+		CREATE TABLE test_1839 (
+		  col Enum8('a\'b' = 1, 'c\'d' = 2, 'a\'b\'c' = 3)
+		) ENGINE = MergeTree ORDER BY tuple()
+	`), "Create table failed")
+
+	t.Cleanup(func() {
+		if err := conn.Exec(context.Background(), "DROP TABLE IF EXISTS test_1839"); err != nil {
+			t.Logf("DROP TABLE test_1839 failed: %v", err)
+		}
+	})
+
+	batch, err := conn.PrepareBatch(t.Context(), "INSERT INTO test_1839")
+	require.NoError(t, err, "PrepareBatch failed")
+	require.NoError(t, batch.Append("a'b"), "Append failed for %q", "a'b")
+	require.NoError(t, batch.Append("c'd"), "Append failed for %q", "c'd")
+	require.NoError(t, batch.Append("a'b'c"), "Append failed for %q", "a'b'c")
+	require.NoError(t, batch.Send(), "Send failed")
+
+	rows, err := conn.Query(t.Context(), "SELECT col FROM test_1839 ORDER BY col")
+	require.NoError(t, err, "SELECT col failed")
+	defer rows.Close()
+
+	var results []string
+	for rows.Next() {
+		var s string
+		require.NoError(t, rows.Scan(&s))
+		results = append(results, s)
+	}
+	require.NoError(t, rows.Err(), "Scan failed")
+	require.Equal(t, []string{"a'b", "c'd", "a'b'c"}, results)
+}
+
+func Test1839HTTP(t *testing.T) {
+	testEnv, err := clickhouse_tests.GetTestEnvironment("issues")
+	require.NoError(t, err)
+	conn, err := clickhouse_tests.GetConnection("issues", t, clickhouse.HTTP, clickhouse_tests.TestClientDefaultSettings(testEnv), nil, nil)
+	require.NoError(t, err)
+	t.Cleanup(func() { conn.Close() })
+
+	require.NoError(t, conn.Exec(t.Context(), `
+		CREATE TABLE test_1839_http (
+		  col Enum8('a\'b' = 1, 'c\'d' = 2, 'a\'b\'c' = 3)
+		) ENGINE = MergeTree ORDER BY tuple()
+	`), "Create table failed")
+
+	t.Cleanup(func() {
+		if err := conn.Exec(context.Background(), "DROP TABLE IF EXISTS test_1839_http"); err != nil {
+			t.Logf("DROP TABLE test_1839_http failed: %v", err)
+		}
+	})
+
+	batch, err := conn.PrepareBatch(t.Context(), "INSERT INTO test_1839_http")
+	require.NoError(t, err, "PrepareBatch failed")
+	require.NoError(t, batch.Append("a'b"), "Append failed for %q", "a'b")
+	require.NoError(t, batch.Append("c'd"), "Append failed for %q", "c'd")
+	require.NoError(t, batch.Append("a'b'c"), "Append failed for %q", "a'b'c")
+	require.NoError(t, batch.Send(), "Send failed")
+
+	rows, err := conn.Query(t.Context(), "SELECT col FROM test_1839_http ORDER BY col")
+	require.NoError(t, err, "SELECT col failed")
+	defer rows.Close()
+
+	var results []string
+	for rows.Next() {
+		var s string
+		require.NoError(t, rows.Scan(&s))
+		results = append(results, s)
+	}
+	require.NoError(t, rows.Err(), "Scan failed")
+	require.Equal(t, []string{"a'b", "c'd", "a'b'c"}, results)
+}