fix(mime-parsing): ensure that text content for multipart nodes always ends with a newline. Fixes #571

Gruntfile.js

@@ -58,4 +58,5 @@ module.exports = function (grunt) {
     // Tasks
     grunt.registerTask('default', ['eslint', 'shell:server', 'wait:server', 'mochaTest', 'shell:server:kill']);
     grunt.registerTask('testonly', ['shell:server', 'wait:server', 'mochaTest', 'shell:server:kill']);
+    grunt.registerTask('proto', ['mochaTest:imap']);
 };

imap-core/lib/indexer/parse-mime-tree.js

@@ -125,6 +125,23 @@ class MIMEParser {
                     node.message = parse(node.body.join(''));
                 }
 
+                if (node.body && node.body.length && node.multipart) {
+                    // find last character from an array of strings
+                    let lastChar;
+                    let lastIndex = 0;
+                    for (let i = node.body.length - 1; i >= 0; i--) {
+                        if (typeof node.body[i] === 'string' && node.body[i].length) {
+                            lastChar = node.body[i].at(-1);
+                            lastIndex = i;
+                            break;
+                        }
+                    }
+                    if (lastChar && lastChar !== '\n') {
+                        // ensure that non-multipart body text always ends with a newline
+                        node.body[lastIndex] += '\n';
+                    }
+                }
+
                 node.lineCount = node.body.length ? node.body.length - 1 : 0;
                 node.body = Buffer.from(
                     node.body

imap-core/test/fixtures/no_empty_line_between_text_boundary.eml

@@ -0,0 +1,22 @@
+Content-Type: multipart/mixed; boundary="------------cWFvDSey27tFG0hVYLqp9hs9"
+MIME-Version: 1.0
+Message-ID: <beep-boop@example-1.com>
+To: foo-1@example-1.com
+From: foo-1@example-1.com
+Subject: test
+
+This is a multi-part message in MIME format.
+--------------cWFvDSey27tFG0hVYLqp9hs9
+Content-Type: text/plain; charset=UTF-8; format=flowed
+Content-Transfer-Encoding: 7bit
+
+test
+
+--------------cWFvDSey27tFG0hVYLqp9hs9
+Content-Type: text/plain; charset=UTF-8; name="example.txt"
+Content-Disposition: attachment; filename="example.txt"
+Content-Transfer-Encoding: base64
+
+ZXhhbXBsZQo=
+
+--------------cWFvDSey27tFG0hVYLqp9hs9--

imap-core/test/fixtures/no_empty_line_between_text_boundary.eml.2

@@ -0,0 +1,22 @@
+Content-Type: multipart/mixed; boundary="------------cWFvDSey27tFG0hVYLqp9hs9"
+MIME-Version: 1.0
+Message-ID: <beep-boop@example-1.com>
+To: foo-1@example-1.com
+From: foo-1@example-1.com
+Subject: test
+
+This is a multi-part message in MIME format.
+--------------cWFvDSey27tFG0hVYLqp9hs9
+Content-Type: text/plain; charset=UTF-8; format=flowed
+Content-Transfer-Encoding: 7bit
+
+test
+
+--------------cWFvDSey27tFG0hVYLqp9hs9
+Content-Type: text/plain; charset=UTF-8; name="example.txt"
+Content-Disposition: attachment; filename="example.txt"
+Content-Transfer-Encoding: base64
+
+ZXhhbXBsZQo=
+
+--------------cWFvDSey27tFG0hVYLqp9hs9--

imap-core/test/parse-mime-tree-test.js

@@ -3,11 +3,20 @@
 'use strict';
 
 const MIMEParser = require('../lib/indexer/parse-mime-tree').MIMEParser;
+const Indexer = require('../lib/indexer/indexer');
+const indexer = new Indexer();
 
+const fs = require('fs');
 const chai = require('chai');
 const expect = chai.expect;
 chai.config.includeStack = true;
 
+const fixtures = {
+    no_empty_line_between_text_boundary: {
+        eml: fs.readFileSync(__dirname + '/fixtures/no_empty_line_between_text_boundary.eml')
+    }
+};
+
 describe('#parseValueParams', function () {
     it('should return continuation value as mime-word', function () {
         let parser = new MIMEParser();
@@ -44,4 +53,23 @@ describe('#parseValueParams', function () {
             hasParams: true
         });
     });
+
+    it('should parse a file with no empty line between text and boundary', function (done) {
+        // parse a file and then make sure that boundary is correct
+
+        let source = Buffer.concat([fixtures.no_empty_line_between_text_boundary.eml]);
+
+        let parser = new MIMEParser(source);
+
+        parser.parse();
+        parser.finalizeTree();
+
+        let parsed = parser.tree.childNodes[0];
+
+        indexer.bodyQuery(parsed, '', (err, data) => {
+            expect(err).to.not.exist;
+            expect(data.toString().indexOf('This is a multi-part message in MIME format.\r\n--------------cWFvDSey27tFG0hVYLqp9hs9')).to.gt(0);
+            done();
+        });
+    });
 });

package.json

@@ -5,6 +5,7 @@
     "main": "server.js",
     "scripts": {
         "test": "mongo --eval 'db.dropDatabase()' wildduck-test && redis-cli -n 13 flushdb && npm run runtest",
+        "test:proto": "NODE_ENV=test grunt proto",
         "printconf": "NODE_CONFIG_ONLY=true npm start",
         "runtest": "NODE_ENV=test grunt",
         "runci": "npm run printconf && npm run runtest",