From 01c3e66989ddf4f3a258b992a406e7d99f6d3c88 Mon Sep 17 00:00:00 2001
From: "Josef M. Gallmetzer" <64498081+galjos@users.noreply.github.com>
Date: Wed, 2 Sep 2026 14:47:40 +0200
Subject: [PATCH] Stop traffic search matching alphabetic terms inside words
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

Place queries like "auer" were matching "Stützmauern" via substring.
Require a word-boundary prefix so municipalities match as words while
cycle aliases and SS12/SS 12 spelling keep working. Refs #12.
---
 CHANGELOG.md                      |  8 ++++++++
 internal/commands/traffic.go      | 16 +++++++++++++++-
 internal/commands/traffic_test.go | 26 ++++++++++++++++++++++++++
 3 files changed, 49 insertions(+), 1 deletion(-)

diff --git a/CHANGELOG.md b/CHANGELOG.md
index a954204..0a19efb 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -8,6 +8,14 @@ SPDX-License-Identifier: CC0-1.0
 
 All notable changes to `odh-cli` are documented here.
 
+## Unreleased
+
+- `traffic search` no longer matches alphabetic terms inside other words.
+  Searching `auer` used to hit every `Stützmauern` notice; terms now match at a
+  word boundary (prefix still allowed, so cycle aliases like `radweg` keep
+  finding `Radrouten`). Road-number spelling (`SS12` / `SS 12`) is unchanged.
+  Refs #12.
+
 ## v0.6.1 - 2026-08-04
 
 - Removed a helper left behind by the v0.6.0 zone-filter refactor. It was dead
diff --git a/internal/commands/traffic.go b/internal/commands/traffic.go
index e3b6695..5fb5b47 100644
--- a/internal/commands/traffic.go
+++ b/internal/commands/traffic.go
@@ -757,7 +757,10 @@ func trafficSearchMatches(event trafficEvent, search string) bool {
 			if term == "" {
 				continue
 			}
-			if strings.Contains(haystack, term) || slices.Contains(identifiers, term) {
+			// Alphabetic terms match at a word boundary only (prefix of a word is
+			// fine: cycle aliases like "radweg" must still find "Radrouten"). An
+			// infix match would turn "auer" into every "Stützmauern".
+			if trafficTextHasTerm(haystack, term) || slices.Contains(identifiers, term) {
 				matched = true
 				break
 			}
@@ -773,6 +776,17 @@ func trafficSearchMatches(event trafficEvent, search string) bool {
 	return true
 }
 
+// trafficTextHasTerm reports whether term sits at the start of any word in
+// haystack. Prefixes are allowed; infix matches inside a longer word are not.
+func trafficTextHasTerm(haystack, term string) bool {
+	for _, word := range strings.Fields(haystack) {
+		if strings.HasPrefix(word, term) {
+			return true
+		}
+	}
+	return false
+}
+
 func trafficSearchTermGroups(search string) [][]string {
 	terms := joinRoadTokens(strings.Fields(normalizeTrafficSearchText(search)))
 	groups := make([][]string, 0, len(terms))
diff --git a/internal/commands/traffic_test.go b/internal/commands/traffic_test.go
index fd4a53c..3927cdc 100644
--- a/internal/commands/traffic_test.go
+++ b/internal/commands/traffic_test.go
@@ -60,3 +60,29 @@ func TestTrafficSearchCycleAliasesAgree(t *testing.T) {
 		}
 	}
 }
+
+// Place-name searches must not match inside unrelated words. "auer" is a real
+// Unterland municipality; matching "Stützmauern" made the content search lie.
+func TestTrafficSearchRequiresWordBoundary(t *testing.T) {
+	wall := trafficEvent{Place: "Bei Moos im Bereich Stuller Wasserfall: Stützmauern erneuern"}
+	if trafficSearchMatches(wall, "auer") {
+		t.Error("auer must not match inside Stützmauern")
+	}
+	town := trafficEvent{Place: "Auer: Baustelle auf der Hauptstrasse"}
+	if !trafficSearchMatches(town, "auer") {
+		t.Error("auer must still match the municipality name as a word")
+	}
+	// Cycle aliases stay prefix matches at a word boundary: "radweg" finds
+	// "Radrouten", and road numbers keep their own spelling path.
+	routes := trafficEvent{Place: "Die Radrouten und die ciclabile bei Auer sind gesperrt"}
+	if !trafficSearchMatches(routes, "radweg") {
+		t.Error("radweg must still prefix-match Radrouten")
+	}
+	if !trafficSearchMatches(routes, "ciclabil") {
+		t.Error("ciclabil must still prefix-match ciclabile")
+	}
+	road := trafficEvent{Place: "Kreuzung mit der SS 12 Brennerstaatsstrasse"}
+	if !trafficSearchMatches(road, "ss12") {
+		t.Error("ss12 must still match spaced road numbers")
+	}
+}