Autocomplete changeset comments from previous changeset comments

Fixes #2002

js/id/core/connection.js

@@ -322,6 +322,23 @@ iD.Connection = function(useHttps) {
         oauth.xhr({ method: 'GET', path: '/api/0.6/user/details' }, done);
     };
 
+    connection.userChangesets = function(callback) {
+        connection.userDetails(function(err, user) {
+            if (err) return callback(err);
+
+            function done(changesets) {
+                callback(undefined, Array.prototype.map.call(changesets.getElementsByTagName('changeset'),
+                    function (changeset) {
+                        return { tags: getTags(changeset) };
+                    }));
+            }
+
+            d3.xml(url + '/api/0.6/changesets?user=' + user.id).get()
+                .on('load', done)
+                .on('error', callback);
+        });
+    };
+
     connection.status = function(callback) {
         function done(capabilities) {
             var apiStatus = capabilities.getElementsByTagName('status');

js/id/ui/commit.js

@@ -38,16 +38,35 @@ iD.ui.Commit = function(context) {
             .attr('placeholder', t('commit.description_placeholder'))
             .attr('maxlength', 255)
             .property('value', context.storage('comment') || '')
-            .on('input.save', function() {
-                d3.selectAll('.save-section .save-button')
-                    .attr('disabled', (this.value.length ? null : true));
-            })
+            .on('input.save', enableDisableSaveButton)
+            .on('change.save', enableDisableSaveButton)
             .on('blur.save', function() {
                 context.storage('comment', this.value);
             });
 
+        function enableDisableSaveButton() {
+            d3.selectAll('.save-section .save-button')
+                .attr('disabled', (this.value.length ? null : true));
+        }
+
         commentField.node().select();
 
+        context.connection().userChangesets(function (err, changesets) {
+            if (err) return;
+
+            var comments = [];
+
+            for (var i = 0; i < changesets.length; i++) {
+                if (changesets[i].tags.comment) {
+                    comments.push({
+                        title: changesets[i].tags.comment,
+                        value: changesets[i].tags.comment
+                    });
+                }
+            }
+
+            commentField.call(d3.combobox().data(comments));
+        });
 
         // Warnings
         var warnings = body.selectAll('div.warning-section')

test/spec/core/connection.js

@@ -248,6 +248,44 @@ describe('iD.Connection', function () {
         });
     });
 
+    describe('#userChangesets', function() {
+        var server,
+            changesetsXML = '<?xml version="1.0" encoding="UTF-8"?><osm>' +
+                '<changeset id="36777543" user="Steve" uid="1" created_at="2016-01-24T15:02:06Z" closed_at="2016-01-24T15:02:07Z" open="false" min_lat="39.3823819" min_lon="-104.8639728" max_lat="39.3834184" max_lon="-104.8618622" comments_count="0">' +
+                '<tag k="comment" v="Caprice Court has been extended"/>' +
+                '<tag k="created_by" v="iD 1.8.5"/>' +
+                '</changeset>' +
+                '</osm>';
+
+        beforeEach(function() {
+            server = sinon.fakeServer.create();
+        });
+
+        afterEach(function() {
+            server.restore();
+        });
+
+        it('loads user changesets', function(done) {
+            c.userDetails = function (callback) {
+                callback(undefined, { id: 1 });
+            };
+
+            c.userChangesets(function(err, changesets) {
+                expect(changesets).to.deep.equal([{
+                    tags: {
+                        comment: 'Caprice Court has been extended',
+                        created_by: 'iD 1.8.5'
+                    }
+                }]);
+                done();
+            });
+
+            server.respondWith("GET", "http://www.openstreetmap.org/api/0.6/changesets?user=1",
+                [200, { "Content-Type": "text/xml" }, changesetsXML]);
+            server.respond();
+        });
+    });
+
     describe('#changesetTags', function() {
         it('omits comment when empty', function() {
             expect(c.changesetTags('', [])).not.to.have.property('comment');