Merge pull request #94 from google/jsclosure-patch

Fix bug #89 for js/closure

Author: drinckes

js/closure/openlocationcode.js

@@ -408,30 +408,30 @@ function recoverNearest(
   // The resolution (height and width) of the padded area in degrees.
   var resolution = Math.pow(20, 2 - (paddingLength / 2));
   // Distance from the center to an edge (in degrees).
-  var areaToEdge = resolution / 2.0;
+  var halfResolution = resolution / 2.0;
 
   // Use the reference location to pad the supplied short code and decode it.
   var codeArea = decode(
-      encode(referenceLatitude, referenceLongitude).substr(0, paddingLength) +
-      shortCode);
+      encode(referenceLatitude, referenceLongitude).substr(0, paddingLength) + shortCode);
   // How many degrees latitude is the code from the reference? If it is more
-  // than half the resolution, we need to move it east or west.
-  var degreesDifference = codeArea.latitudeCenter - referenceLatitude;
-  if (degreesDifference > areaToEdge) {
-    // If the center of the short code is more than half a cell east,
-    // then the best match will be one position west.
+  // than half the resolution, we need to move it north or south but keep it
+  // within -90 to 90 degrees.
+  if (referenceLatitude + halfResolution < codeArea.latitudeCenter &&
+      codeArea.latitudeCenter - resolution >= -LATITUDE_MAX) {
+    // If the proposed code is more than half a cell north of the reference location,
+    // it's too far, and the best match will be one cell south.
     codeArea.latitudeCenter -= resolution;
-  } else if (degreesDifference < -areaToEdge) {
-    // If the center of the short code is more than half a cell west,
-    // then the best match will be one position east.
+  } else if (referenceLatitude - halfResolution > codeArea.latitudeCenter &&
+             codeArea.latitudeCenter + resolution <= LATITUDE_MAX) {
+    // If the proposed code is more than half a cell south of the reference location,
+    // it's too far, and the best match will be one cell north.
     codeArea.latitudeCenter += resolution;
   }
 
   // How many degrees longitude is the code from the reference?
-  degreesDifference = codeArea.longitudeCenter - referenceLongitude;
-  if (degreesDifference > areaToEdge) {
+  if (referenceLongitude + halfResolution < codeArea.longitudeCenter) {
     codeArea.longitudeCenter -= resolution;
-  } else if (degreesDifference < -areaToEdge) {
+  } else if (referenceLongitude - halfResolution > codeArea.longitudeCenter) {
     codeArea.longitudeCenter += resolution;
   }
 

js/closure/openlocationcode_test.js

@@ -256,6 +256,10 @@ testSuite({
       assertEquals('Test ' + i, recovered, td[0]);
     }
   },
+  testRecoveryNearPoles: function() {
+    assertEquals("2CXXXXXX+XX", OpenLocationCode.recoverNearest("XXXXXX+XX", -81.0, 0.0));
+    assertEquals("CFX22222+22", OpenLocationCode.recoverNearest("2222+22", 89.6, 0.0));
+  },
   testValidity: function() {
     var tests = [
       //   code,isValid,isShort,isFull