fix: Sanitize OSM height values with comma decimal separators

tiles/src/main/java/com/protomaps/basemap/layers/Buildings.java

@@ -36,6 +36,29 @@ public record Height(Double height, Double min_height) {}
 
   static final Pattern pattern = Pattern.compile("^\\d+(\\.\\d)?$");
 
+  static final Pattern COMMA_DECIMAL_PATTERN = Pattern.compile(",(?=\\d{1,2}(\\s*[a-zA-Z]*)?$)");
+
+  /**
+   * Sanitizes height values by fixing common OSM tagging mistakes.
+   * Specifically handles commas used as decimal separators (e.g., "89,10" -> "89.10").
+   *
+   * @param value the raw height value from OSM
+   * @return sanitized value
+   */
+  static String sanitizeHeightValue(String value) {
+    if (value == null || value.isEmpty()) {
+      return value;
+    }
+
+    // Replace comma with period if followed by 1 or 2 digits (optional unit suffix)
+    // This handles cases like: "89,1", "89,10", "89,1 m", "89,1m"
+    // Pattern explanation:
+    // - Match a comma followed by 1-2 digits
+    // - Optionally followed by whitespace and/or unit characters (like 'm')
+    // - Leave other commas unchanged (e.g., thousands separators like "1,000")
+    return COMMA_DECIMAL_PATTERN.matcher(value).replaceFirst(".");
+  }
+
   static Double parseWellFormedDouble(String s) {
     if (pattern.matcher(s).matches()) {
       return parseDoubleOrNull(s);
@@ -44,15 +67,15 @@ static Double parseWellFormedDouble(String s) {
   }
 
   static Height parseHeight(String osmHeight, String osmLevels, String osmMinHeight) {
-    var height = parseDoubleOrNull(osmHeight);
+    var height = parseDoubleOrNull(sanitizeHeightValue(osmHeight));
     if (height == null) {
       Double levels = parseDoubleOrNull(osmLevels);
       if (levels != null) {
         height = Math.max(levels, 1) * 3 + 2;
       }
     }
 
-    return new Height(height, parseDoubleOrNull(osmMinHeight));
+    return new Height(height, parseDoubleOrNull(sanitizeHeightValue(osmMinHeight)));
   }
 
   static int quantizeVal(double val, int step) {

tiles/src/test/java/com/protomaps/basemap/layers/BuildingsTest.java

@@ -51,6 +51,25 @@ void parseBuildingHeights() {
     assertEquals(1, result.min_height());
   }
 
+  @Test
+  void parseBuildingHeightsWithCommaDecimalSeparator() {
+    var result = Buildings.parseHeight("89,10", null, "3,5");
+    assertEquals(89.10, result.height());
+    assertEquals(3.5, result.min_height());
+
+    result = Buildings.parseHeight("89,1 m", null, "3,5 m");
+    assertEquals(89.1, result.height());
+    assertEquals(3.5, result.min_height());
+
+    result = Buildings.parseHeight("89,100 m", null, "3,500");
+    assertEquals(89100, result.height());
+    assertEquals(3500, result.min_height());
+
+    result = Buildings.parseHeight("invalid", null, " ");
+    assertNull(result.height());
+    assertNull(result.min_height());
+  }
+
   @Test
   void parseBuildingHeightsFromLevels() {
     var result = Buildings.parseHeight(null, "3", null);
@@ -59,6 +78,20 @@ void parseBuildingHeightsFromLevels() {
     assertEquals(5, result.height());
   }
 
+  @Test
+  void sanitizeHeightValue() {
+    assertEquals("89.1", Buildings.sanitizeHeightValue("89,1"));
+    assertEquals("89.10", Buildings.sanitizeHeightValue("89,10"));
+    assertEquals("89.1 m", Buildings.sanitizeHeightValue("89,1 m"));
+    assertEquals("89.1 meters", Buildings.sanitizeHeightValue("89,1 meters"));
+    assertEquals("89.1m", Buildings.sanitizeHeightValue("89,1m"));
+    assertEquals("89.10", Buildings.sanitizeHeightValue("89.10"));
+    assertNull(Buildings.sanitizeHeightValue(null));
+    assertEquals("", Buildings.sanitizeHeightValue(""));
+    assertEquals("1,234", Buildings.sanitizeHeightValue("1,234"));
+    assertEquals("3,500", Buildings.sanitizeHeightValue("3,500"));
+    assertEquals("89,100", Buildings.sanitizeHeightValue("89,100"));
+  }
 
   @Test
   void railwayTagIsBuilding() {