From b304e9975a993815f22d2bb4ab1e09f9fee0210d Mon Sep 17 00:00:00 2001
From: slothful-vassal <89943360+slothful-vassal@users.noreply.github.com>
Date: Thu, 4 Jun 2026 17:47:04 +0200
Subject: [PATCH] fix polyline db field size (#1047)

---
 .../1778583700_updated_trails_polyline_max.go | 36 +++++++++++++++++++
 db/util/polyline.go                           |  6 ++++
 2 files changed, 42 insertions(+)
 create mode 100644 db/migrations/1778583700_updated_trails_polyline_max.go

diff --git a/db/migrations/1778583700_updated_trails_polyline_max.go b/db/migrations/1778583700_updated_trails_polyline_max.go
new file mode 100644
index 00000000..dc077eb4
--- /dev/null
+++ b/db/migrations/1778583700_updated_trails_polyline_max.go
@@ -0,0 +1,36 @@
+package migrations
+
+import (
+	"pocketbase/util"
+
+	"github.com/pocketbase/pocketbase/core"
+	m "github.com/pocketbase/pocketbase/migrations"
+)
+
+func init() {
+	m.Register(func(app core.App) error {
+		collection, err := app.FindCollectionByNameOrId("e864strfxo14pm4")
+		if err != nil {
+			return err
+		}
+
+		field, ok := collection.Fields.GetByName("polyline").(*core.TextField)
+		if ok {
+			field.Max = util.PolylineMaxLength
+		}
+
+		return app.Save(collection)
+	}, func(app core.App) error {
+		collection, err := app.FindCollectionByNameOrId("e864strfxo14pm4")
+		if err != nil {
+			return err
+		}
+
+		field, ok := collection.Fields.GetByName("polyline").(*core.TextField)
+		if ok {
+			field.Max = 0
+		}
+
+		return app.Save(collection)
+	})
+}
diff --git a/db/util/polyline.go b/db/util/polyline.go
index 4b782909..291a740e 100644
--- a/db/util/polyline.go
+++ b/db/util/polyline.go
@@ -10,6 +10,8 @@ import (
 	"github.com/twpayne/go-polyline"
 )
 
+const PolylineMaxLength = 5 * 1024 * 1024
+
 func ComputePolyline(app core.App, r *core.Record) (string, error) {
 	gpxPath := r.GetString("gpx")
 	if len(gpxPath) == 0 {
@@ -56,6 +58,10 @@ func SavePolyline(app core.App, r *core.Record) error {
 	if err != nil {
 		return err
 	}
+	// Encoded polylines are ASCII-only, so byte length matches character length.
+	if len(encoded) > PolylineMaxLength {
+		return fmt.Errorf("polyline exceeds maximum length of %d characters", PolylineMaxLength)
+	}
 	r.Set("polyline", encoded)
 	if err := app.UnsafeWithoutHooks().Save(r); err != nil {
 		return fmt.Errorf("save trail polyline: %w", err)