mesh-mail: group-by-sender and order-by sender compare addresses case-insensitively in Postgres too, and a sender's shown name and address are its newest mail's, deterministically (issue 1230, review finding 6)

modules/mesh-mail/cmd/mesh-mail/pgstore.go

@@ -561,7 +561,7 @@ func searchWhere(q Query) (whereSQL string, args []any) {
 // unknown or empty answers "date" — the tool refuses an unknown order-by before the store is ever asked (AC16).
 var orderColumns = map[string]string{
 	"date":    "date",
-	"sender":  "coalesce(sender->0->>'address', '')",
+	"sender":  "lower(coalesce(sender->0->>'address', ''))",
 	"subject": "subject",
 	"size":    "size",
 }
@@ -620,9 +620,16 @@ func (s *PgStore) GroupBySender(ctx context.Context, q Query) ([]SenderGroup, er
 		args = append(args, v)
 		return fmt.Sprintf("$%d", len(args))
 	}
-	sqlText := `select el->>'address' as address, max(el->>'name') as name, count(*) as count, max(date) as newest
+	// Review round 1 finding 6: grouped by lower(address) (not case-sensitively, as a mixed-case repeat of the
-		from message, jsonb_array_elements(sender) el where ` + whereSQL + ` group by el->>'address'
+	// same address would otherwise split into two lines); name and address are the newest mail's own
-		order by count desc, address asc limit ` + param(limit)
+	// (array_agg ordered by date, its first element), never max()'s lexicographically largest, which is neither.
+	// The outer select re-sorts by lower(address): Postgres resolves a SELECT alias used bare in order by, but
+	// not wrapped in a function, so the grouping is wrapped in its own subquery first.
+	sqlText := `select address, name, count, newest from (
+		select (array_agg(el->>'address' order by date desc))[1] as address,
+			(array_agg(el->>'name' order by date desc))[1] as name, count(*) as count, max(date) as newest
+		from message, jsonb_array_elements(sender) el where ` + whereSQL + ` group by lower(el->>'address')
+		) grouped order by count desc, lower(address) asc limit ` + param(limit)
 	rows, err := s.pool.Query(ctx, sqlText, args...)
 	if err != nil {
 		return nil, err

modules/mesh-mail/cmd/mesh-mail/search_test.go

@@ -9,6 +9,7 @@ package main
 import (
 	"context"
 	"sort"
+	"strings"
 	"testing"
 	"time"
 )
@@ -529,6 +530,52 @@ func TestGroupBySenderOrdersByCountDescending(t *testing.T) {
 	})
 }
 
+// 1230 (review round 1 finding 6): the same address, written differently across two mails, is one sender, not
+// two — grouped case-insensitively, in both stores. Its displayed address and name are the newest mail's own
+// (not max()'s lexicographically largest, and not whichever memStore's map iteration visited first), and
+// order-by sender compares case-insensitively too.
+func TestGroupBySenderAndOrderBySenderAreCaseInsensitive(t *testing.T) {
+	eachStore(t, func(t *testing.T, st Store) {
+		ctx := context.Background()
+		older := time.Date(2026, 10, 1, 9, 0, 0, 0, time.UTC)
+		newer := time.Date(2026, 10, 2, 9, 0, 0, 0, time.UTC)
+		for _, m := range []Message{
+			{Account: "mixedcase", Folder: "INBOX", UID: 1, MessageID: "<mc1>", Subject: "first", Date: older,
+				From: []Person{{Name: "Bob", Address: "Bob@Example.ORG"}}, To: []Person{}, Flags: []string{}, Attachments: []AttachmentRef{}},
+			{Account: "mixedcase", Folder: "INBOX", UID: 2, MessageID: "<mc2>", Subject: "second", Date: newer,
+				From: []Person{{Name: "Bobby", Address: "bob@example.org"}}, To: []Person{}, Flags: []string{}, Attachments: []AttachmentRef{}},
+			{Account: "mixedcase", Folder: "INBOX", UID: 3, MessageID: "<mc3>", Subject: "third", Date: older.Add(time.Hour),
+				From: []Person{{Name: "Alice", Address: "alice@example.org"}}, To: []Person{}, Flags: []string{}, Attachments: []AttachmentRef{}},
+		} {
+			if err := st.Add(ctx, m, nil); err != nil {
+				t.Fatal(err)
+			}
+		}
+		groups, err := st.GroupBySender(ctx, Query{Accounts: []string{"mixedcase"}, Folder: "INBOX", Limit: 10})
+		if err != nil {
+			t.Fatal(err)
+		}
+		if len(groups) != 2 {
+			t.Fatalf("Bob@Example.ORG and bob@example.org were not merged into one sender: %+v", groups)
+		}
+		var bob *SenderGroup
+		for i := range groups {
+			if strings.EqualFold(groups[i].Address, "bob@example.org") {
+				bob = &groups[i]
+			}
+		}
+		if bob == nil || bob.Count != 2 || bob.Address != "bob@example.org" || bob.Name != "Bobby" || !bob.Newest.Equal(newer) {
+			t.Fatalf("bob's merged line: %+v", bob)
+		}
+
+		bySender, err := st.Search(ctx, Query{Accounts: []string{"mixedcase"}, Folder: "INBOX", OrderBy: "sender", Limit: 10})
+		if err != nil {
+			t.Fatal(err)
+		}
+		sameOrder(t, bySender, "<mc3>", "<mc1>", "<mc2>") // alice@... before Bob@.../bob@... (case-insensitive)
+	})
+}
+
 // 1231/AC8: in-reply-to a mail I sent, combined with from (its recipient), answers the replies to it; alone, it
 // answers every reply in the thread's direct answer set.
 func TestSearchFiltersByInReplyTo(t *testing.T) {

modules/mesh-mail/cmd/mesh-mail/store.go

@@ -455,13 +455,17 @@ func (s *memStore) GroupBySender(_ context.Context, q Query) ([]SenderGroup, err
 			addr := strings.ToLower(p.Address)
 			g, ok := byAddress[addr]
 			if !ok {
-				g = &SenderGroup{Address: p.Address, Name: p.Name}
+				g = &SenderGroup{}
 				byAddress[addr] = g
 				order = append(order, addr)
 			}
 			g.Count++
-			if m.Date.After(g.Newest) {
+			// Review round 1 finding 6: Address and Name are the newest mail's own, never whichever message a
+			// Go map's (randomised) iteration order happened to visit first.
+			if g.Newest.IsZero() || m.Date.After(g.Newest) {
 				g.Newest = m.Date
+				g.Address = p.Address
+				g.Name = p.Name
 			}
 		}
 	}
@@ -473,7 +477,7 @@ func (s *memStore) GroupBySender(_ context.Context, q Query) ([]SenderGroup, err
 		if out[i].Count != out[j].Count {
 			return out[i].Count > out[j].Count
 		}
-		return out[i].Address < out[j].Address
+		return strings.ToLower(out[i].Address) < strings.ToLower(out[j].Address)
 	})
 	if q.Limit > 0 && len(out) > q.Limit {
 		out = out[:q.Limit]