Fixing issue uncovered by test case.

packages/server/src/api/controllers/row/staticFormula.ts

@@ -19,6 +19,17 @@ import { cloneDeep, merge } from "lodash/fp"
 import sdk from "../../../sdk"
 import * as pro from "@budibase/pro"
 
+function mergeRows(row1: Row, row2: Row) {
+  const merged = merge(row1, row2)
+  // make sure any specifically undefined fields are removed
+  for (const key of Object.keys(row2)) {
+    if (row2[key] === undefined) {
+      delete merged[key]
+    }
+  }
+  return merged
+}
+
 /**
  * This function runs through a list of enriched rows, looks at the rows which
  * are related and then checks if they need the state of their formulas
@@ -164,7 +175,11 @@ export async function finaliseRow(
 
   await db.put(row)
   const retrieved = await db.tryGet<Row>(row._id)
-  enrichedRow = merge(retrieved, enrichedRow)
+  if (!retrieved) {
+    throw new Error(`Unable to retrieve row ${row._id} after saving.`)
+  }
+
+  enrichedRow = mergeRows(retrieved, enrichedRow)
   enrichedRow = await processFormulas(table, enrichedRow, {
     dynamic: false,
   })

packages/server/src/api/routes/tests/row.spec.ts

@@ -2571,14 +2571,12 @@ if (descriptions.length) {
         let tableId: string
         let o2mData: Row[]
         let m2mData: Row[]
-        let isRelationship: boolean
 
         beforeAll(async () => {
           const table = await config.api.table.save(
             defaultTable({ schema: relSchema() })
           )
           tableId = table._id!
-          isRelationship = relSchema().user.type === FieldType.LINK
 
           o2mData = [
             await dataGenerator(o2mTable._id!),
@@ -2755,19 +2753,8 @@ if (descriptions.length) {
             user: null,
             users: null,
           })
-          expect(updatedRow).toEqual({
-            name: "foo",
-            description: "bar",
-            tableId,
-            _id: row._id,
-            _rev: expect.any(String),
-            id: isInternal ? undefined : expect.any(Number),
-            type: isInternal ? "row" : undefined,
-            createdAt: isInternal ? new Date().toISOString() : undefined,
-            updatedAt: isInternal ? new Date().toISOString() : undefined,
-            users: isRelationship ? undefined : [],
-            user: isRelationship ? undefined : [],
-          })
+          expect(updatedRow.user).toBeUndefined()
+          expect(updatedRow.users).toBeUndefined()
         })
 
         it("fetch all will populate the relationships", async () => {

packages/server/src/utilities/rowProcessor/bbReferenceProcessor.ts

@@ -153,10 +153,10 @@ export async function processOutputBBReference(
 }
 
 export async function processOutputBBReferences(
-  value: string | null | undefined,
+  value: string | string[] | null | undefined,
   subtype: BBReferenceFieldSubType
 ): Promise<UserReferenceInfo[] | undefined> {
-  if (!value) {
+  if (!value || (Array.isArray(value) && value.length === 0)) {
     return undefined
   }
   const ids =