Fix format=flowed unfolding on quoted lines; added tests for rcube_mime::format_flowed() and rcube_mime::unfold_flowed()

program/lib/Roundcube/rcube_mime.php

@@ -480,7 +480,8 @@ class rcube_mime
                 $q = strlen(str_replace(' ', '', $regs[0]));
                 $line = substr($line, strlen($regs[0]));
 
-                if ($q == $q_level && $line
+                if ($q == $q_level
+                    && strlen($line[$last]) > 1  // don't hit if line only consist of one single white space
                     && isset($text[$last])
                     && $text[$last][strlen($text[$last])-1] == ' '
                 ) {

tests/Framework/Mime.php

@@ -120,4 +120,26 @@ class Framework_Mime extends PHPUnit_Framework_TestCase
             $this->assertEquals($item['out'], $res, "Header decoding for: " . $idx);
         }
     }
+
+    /**
+     * Test format=flowed unfolding
+     */
+    function test_format_flowed()
+    {
+        $raw = file_get_contents(TESTS_DIR . 'src/format-flowed-unfolded.txt');
+        $flowed = file_get_contents(TESTS_DIR . 'src/format-flowed.txt');
+
+        $this->assertEquals($flowed, rcube_mime::format_flowed($raw, 80), "Test correct folding and space-stuffing");
+    }
+
+    /**
+     * Test format=flowed unfolding
+     */
+    function test_unfold_flowed()
+    {
+        $flowed = file_get_contents(TESTS_DIR . 'src/format-flowed.txt');
+        $unfolded = file_get_contents(TESTS_DIR . 'src/format-flowed-unfolded.txt');
+
+        $this->assertEquals($unfolded, rcube_mime::unfold_flowed($flowed), "Test correct unfolding of quoted lines");
+    }
 }

tests/src/format-flowed-unfolded.txt

@@ -0,0 +1,14 @@
+I'm replying on this with a very long line which is then wrapped and space-stuffed because the draft is saved as format=flowed.
+From what's specified in RFC 2646 some lines need to be space-stuffed to avoid muning during transport.
+
+X
+
+On XX.YY.YYYY Y:YY, Somebody wrote:
+> This part is a reply wihtout any flowing lines. rcube_mime::unfold_flowed()
+> has to be careful with empty quoted lines because they might end with a
+> space but still shouldn't be considered as flowed!
+> 
+> The above empty line should persist after unfolding.
+> xxxxxxxxxx. xxxx xxxxx xxxxx xxxx xx xx.xx. xxxxxx xxxxxxxxxxxx, xxxx xx
+> 
+> ... and this one as well.

tests/src/format-flowed.txt

@@ -0,0 +1,16 @@
+I'm replying on this with a very long line which is then wrapped and 
+space-stuffed because the draft is saved as format=flowed.
+ From what's specified in RFC 2646 some lines need to be space-stuffed to 
+avoid muning during transport.
+
+X
+
+On XX.YY.YYYY Y:YY, Somebody wrote:
+> This part is a reply wihtout any flowing lines. rcube_mime::unfold_flowed()
+> has to be careful with empty quoted lines because they might end with a
+> space but still shouldn't be considered as flowed!
+> 
+> The above empty line should persist after unfolding.
+> xxxxxxxxxx. xxxx xxxxx xxxxx xxxx xx xx.xx. xxxxxx xxxxxxxxxxxx, xxxx xx
+> 
+> ... and this one as well.