Handle leading comment with no new-line

acceptance_tests/empty.sh

@@ -8,7 +8,27 @@ EOL
 
 testEmptyEval() {
   X=$(./yq e test.yml)
+  expected=$(cat test.yml)
   assertEquals 0 $?
+  assertEquals "$expected" "$X"
+}
+
+testEmptyEvalNoNewLine() {
+  echo -n "#comment" >test.yml
+  X=$(./yq e test.yml)
+  expected=$(cat test.yml)
+  assertEquals 0 $?
+  assertEquals "$expected" "$X"
+}
+
+testEmptyEvalNoNewLineWithExpression() {
+  echo -n "# comment" >test.yml
+  X=$(./yq e '.apple = "tree"' test.yml)
+  read -r -d '' expected << EOM
+# comment
+apple: tree
+EOM
+  assertEquals "$expected" "$X"
 }
 
 testEmptyEvalPipe() {

pkg/yqlib/printer.go

@@ -147,6 +147,12 @@ func (p *resultsPrinter) PrintResults(matchingNodes *list.List) error {
 				}
 
 				if errReading == io.EOF {
+					if readline != "" {
+						// the last comment we read didn't have a new line, put one in
+						if err := p.writeString(bufferedWriter, "\n"); err != nil {
+							return err
+						}
+					}
 					break
 				}
 			}