Some objectGUID buffer cause error in escape filter function

lib/utils/escape-filter-value.js

@@ -27,22 +27,22 @@ function escapeFilterValue (toEscape) {
 }
 
 function escapeBuffer (buf) {
+  const bufLen = buf.byteLength
   let result = ''
   for (let i = 0; i < buf.length; i += 1) {
     if (buf[i] >= 0xc0 && buf[i] <= 0xdf) {
       // Represents the first byte in a 2-byte UTF-8 character.
-      result += '\\' + buf[i].toString(16) + '\\' + buf[i + 1].toString(16)
+      result += '\\' + buf[i].toString(16)
+      if (i < (bufLen - 1)) { result += '\\' + buf[i + 1].toString(16).padStart(2, '0') } // Only add second byte if exist in buffer
       i += 1
       continue
     }
 
     if (buf[i] >= 0xe0 && buf[i] <= 0xef) {
       // Represents the first byte in a 3-byte UTF-8 character.
-      result += [
-        '\\', buf[i].toString(16),
-        '\\', buf[i + 1].toString(16),
-        '\\', buf[i + 2].toString(16)
-      ].join('')
+      result += '\\' + buf[i].toString(16)
+      if (i < (bufLen - 1)) { result += '\\' + buf[i + 1].toString(16).padStart(2, '0') } // Only add second byte if exist in buffer
+      if (i < (bufLen - 2)) { result += '\\' + buf[i + 2].toString(16).padStart(2, '0') } // Only add third byte if exist in buffer
       i += 2
       continue
     }

lib/utils/escape-filter-value.test.js

@@ -83,3 +83,15 @@ tap.test('leaves encoded characters intact', async t => {
     t.equal(result, expected[i])
   }
 })
+
+tap.test('handle start of two byte utf-8 character at end of buffer', async t => {
+  const input = Buffer.from([0x30, 0xc2])
+  const expected = '0\\c2'
+  t.equal(escapeFilterValue(input), expected)
+})
+
+tap.test('handle start of three byte utf-8 character at end of buffer', async t => {
+  const input = Buffer.from([0x30, 0xe2])
+  const expected = '0\\e2'
+  t.equal(escapeFilterValue(input), expected)
+})