Linkify geo: URIs in message bodies

core/util-jvm/src/main/java/org/signal/core/util/Linkifier.kt

@@ -68,19 +68,31 @@ object Linkifier {
   )
 
   /**
-   * Finds all web URLs in [text], in left-to-right order.
+   * Matches a `geo:` URI per RFC 5870 plus Google's `?q=`/`?z=` query extension. Coordinate shape
+   * is permissive here — lat/lon ranges are validated separately by [hasValidGeoCoordinates].
+   */
+  private val GEO_URI_PATTERN: Pattern = Pattern.compile(
+    "(?i)geo:" +
+      "-?\\d{1,3}(?:\\.\\d+)?,-?\\d{1,3}(?:\\.\\d+)?" +
+      "(?:,-?\\d+(?:\\.\\d+)?)?" +
+      "(?:[;?]" + URL_CHAR + "*)?"
+  )
+
+  /**
+   * Finds all web URLs and `geo:` URIs in [text], in left-to-right order.
    */
   @JvmStatic
   fun findLinks(text: CharSequence): List<DetectedLink> {
     if (text.isEmpty()) {
       return emptyList()
     }
 
-    val matcher = WEB_URL_PATTERN.matcher(text)
     val out = ArrayList<DetectedLink>()
-    while (matcher.find()) {
-      val start = matcher.start()
-      val rawEnd = matcher.end()
+
+    val webMatcher = WEB_URL_PATTERN.matcher(text)
+    while (webMatcher.find()) {
+      val start = webMatcher.start()
+      val rawEnd = webMatcher.end()
 
       if (!isAtLeadingBoundary(text, start)) {
         continue
@@ -105,6 +117,36 @@ object Linkifier {
       val normalized = if (raw.contains("://")) raw else "http://$raw"
       out.add(DetectedLink(start, end, normalized))
     }
+
+    val geoMatcher = GEO_URI_PATTERN.matcher(text)
+    while (geoMatcher.find()) {
+      val start = geoMatcher.start()
+      val rawEnd = geoMatcher.end()
+
+      if (!isAtLeadingBoundary(text, start)) {
+        continue
+      }
+
+      val end = trimTrailingNonUrlChars(text, start, rawEnd)
+      if (end <= start) {
+        continue
+      }
+
+      if (end < text.length && isFormatOrZeroWidth(text[end])) {
+        continue
+      }
+
+      val raw = text.subSequence(start, end).toString()
+      if (!hasValidGeoCoordinates(raw)) {
+        continue
+      }
+
+      out.add(DetectedLink(start, end, raw))
+    }
+
+    if (out.size > 1) {
+      out.sortBy { it.start }
+    }
     return out
   }
 
@@ -210,6 +252,20 @@ object Linkifier {
     return tld.lowercase() in TOP_LEVEL_DOMAINS
   }
 
+  /**
+   * Checks that the lat/lon embedded in a geo URI fall within valid Earth ranges. The regex is
+   * permissive so out-of-range coordinates (e.g. lat 91) still need to be rejected here.
+   */
+  private fun hasValidGeoCoordinates(geoUri: String): Boolean {
+    val body = geoUri.substring("geo:".length)
+    val coordEnd = body.indexOfAny(charArrayOf(';', '?')).let { if (it < 0) body.length else it }
+    val parts = body.substring(0, coordEnd).split(',')
+    if (parts.size < 2 || parts.size > 3) return false
+    val lat = parts[0].toDoubleOrNull() ?: return false
+    val lon = parts[1].toDoubleOrNull() ?: return false
+    return lat in -90.0..90.0 && lon in -180.0..180.0
+  }
+
   /** Returns a set containing every entry in [unicode] plus its punycode form (where applicable). */
   private fun withPunycode(unicode: Set<String>): Set<String> {
     val out: MutableSet<String> = HashSet(unicode.size * 2)

core/util-jvm/src/test/java/org/signal/core/util/LinkifierTest.kt

@@ -66,6 +66,7 @@ class LinkifierTest(private val case: Case) {
   companion object {
 
     private fun web(spanText: String, url: String = spanText) = Expected(spanText, url)
+    private fun geo(spanText: String) = Expected(spanText, url = spanText)
 
     @Parameterized.Parameters(name = "{0}")
     @JvmStatic
@@ -177,7 +178,40 @@ class LinkifierTest(private val case: Case) {
       Case("leading bidi override rejects url", "‬moc.diordna.com next", emptyList()),
       Case("trailing bidi override rejects url", "moc.diordna.com‭ next", emptyList()),
       Case("internal bidi override rejects both halves", "moc.diordna.com‮moc.diordna.com", emptyList()),
-      Case("zero-width space adjacent to url rejects it", "see signal.org​ next", emptyList())
+      Case("zero-width space adjacent to url rejects it", "see signal.org​ next", emptyList()),
+
+      // ----- geo URIs -----
+      Case("geo uri with basic coords", "geo:48.2010,16.3695", listOf(geo("geo:48.2010,16.3695"))),
+      Case("geo uri with altitude", "geo:48.2010,16.3695,123", listOf(geo("geo:48.2010,16.3695,123"))),
+      Case("geo uri with uncertainty param", "geo:48.2010,16.3695;u=40", listOf(geo("geo:48.2010,16.3695;u=40"))),
+      Case("geo uri with google query and label", "geo:0,0?q=37.786971,-122.399677(Treasure%20Island)", listOf(geo("geo:0,0?q=37.786971,-122.399677(Treasure%20Island)"))),
+      Case("geo uri with google search query", "geo:0,0?q=Eiffel+Tower", listOf(geo("geo:0,0?q=Eiffel+Tower"))),
+      Case("geo uri with negative coords", "geo:-33.86,151.21", listOf(geo("geo:-33.86,151.21"))),
+      Case("geo uri at origin", "geo:0,0", listOf(geo("geo:0,0"))),
+      Case("geo uri scheme is case insensitive", "GEO:48.2,16.3", listOf(geo("GEO:48.2,16.3"))),
+
+      // ----- geo URI in sentence context -----
+      Case("geo uri followed by sentence period", "Meet at geo:48.2,16.3.", listOf(geo("geo:48.2,16.3"))),
+      Case("geo uri followed by sentence comma", "From geo:48.2,16.3, walk north", listOf(geo("geo:48.2,16.3"))),
+      Case("geo uri inside parens is detected without them", "(geo:48.2,16.3)", listOf(geo("geo:48.2,16.3"))),
+      Case("balanced parens inside geo query are preserved", "place geo:0,0?q=37.78,-122.4(Treasure%20Island) end", listOf(geo("geo:0,0?q=37.78,-122.4(Treasure%20Island)"))),
+      Case("unmatched close paren after geo query is trimmed", "(see geo:0,0?q=foo)", listOf(geo("geo:0,0?q=foo"))),
+      Case("non-numeric altitude falls back to coord-only match", "geo:48,16,foo", listOf(geo("geo:48,16"))),
+
+      // ----- geo URI false-positive guards -----
+      Case("geo with lat over 90 is rejected", "geo:91.0,0", emptyList()),
+      Case("geo with lon over 180 is rejected", "geo:0,181.0", emptyList()),
+      Case("geo with lat below -90 is rejected", "geo:-91,0", emptyList()),
+      Case("geo with non-numeric coords is not matched", "geo:foo,bar", emptyList()),
+      Case("geo glued to a leading letter is rejected", "xgeo:48.2,16.3", emptyList()),
+      Case("geo missing lon is not matched", "geo:48.2", emptyList()),
+      Case("bare geo scheme is not matched", "geo:", emptyList()),
+      Case("whitespace between geo coords breaks the uri", "geo:48.2, 16.3", emptyList()),
+
+      // ----- geo + web mixed -----
+      Case("geo uri then web url ordered left-to-right", "see geo:48.2,16.3 and https://signal.org", listOf(geo("geo:48.2,16.3"), web("https://signal.org"))),
+      Case("web url then geo uri ordered left-to-right", "https://signal.org then geo:48.2,16.3", listOf(web("https://signal.org"), geo("geo:48.2,16.3"))),
+      Case("two geo uris in the same string", "from geo:48.2,16.3 to geo:51.5,-0.1", listOf(geo("geo:48.2,16.3"), geo("geo:51.5,-0.1")))
     ).map { arrayOf<Any>(it) }
   }
 }