[gmime: 5/24] Updated gmime-part encode() method to force 7bit and 8bit to qp if they contain from-lines

[Jeffrey Stedfast <fejj src gnome org>]

commit 1a0b2abdf9629d95f738a245107466875b3603be
Author: Jeffrey Stedfast <jestedfa microsoft com>
Date:   Mon Jul 10 14:55:20 2017 -0400

    Updated gmime-part encode() method to force 7bit and 8bit to qp if they contain from-lines

 gmime/gmime-part.c |   35 ++++++++++++++++++++++-------------
 1 files changed, 22 insertions(+), 13 deletions(-)
---
diff --git a/gmime/gmime-part.c b/gmime/gmime-part.c
index 677bc98..ffa6c68 100644
--- a/gmime/gmime-part.c
+++ b/gmime/gmime-part.c
@@ -432,18 +432,6 @@ mime_part_encode (GMimeObject *object, GMimeEncodingConstraint constraint)
        GMimeFilter *filter;
        
        switch (part->encoding) {
-       case GMIME_CONTENT_ENCODING_DEFAULT:
-               /* Unspecified encoding, we need to figure out the
-                * best encoding no matter what */
-               break;
-       case GMIME_CONTENT_ENCODING_7BIT:
-               /* This encoding is always safe. */
-               return;
-       case GMIME_CONTENT_ENCODING_8BIT:
-               /* This encoding is safe unless the constraint is 7bit. */
-               if (constraint != GMIME_ENCODING_CONSTRAINT_7BIT)
-                       return;
-               break;
        case GMIME_CONTENT_ENCODING_BINARY:
                /* This encoding is only safe if the constraint is binary. */
                if (constraint == GMIME_ENCODING_CONSTRAINT_BINARY)
@@ -454,6 +442,8 @@ mime_part_encode (GMimeObject *object, GMimeEncodingConstraint constraint)
        case GMIME_CONTENT_ENCODING_UUENCODE:
                /* These encodings are always safe. */
                return;
+       default:
+               break;
        }
        
        filter = g_mime_filter_best_new (GMIME_FILTER_BEST_ENCODING);
@@ -467,7 +457,26 @@ mime_part_encode (GMimeObject *object, GMimeEncodingConstraint constraint)
        g_object_unref (stream);
        
        encoding = g_mime_filter_best_encoding ((GMimeFilterBest *) filter, constraint);
-       g_mime_part_set_content_encoding (part, encoding);
+       
+       switch (part->encoding) {
+       case GMIME_CONTENT_ENCODING_DEFAULT:
+               g_mime_part_set_content_encoding (part, encoding);
+               break;
+       case GMIME_CONTENT_ENCODING_7BIT:
+               /* This encoding is generally safe, but we may need to encode From-lines. */
+               if (((GMimeFilterBest *) filter)->hadfrom)
+                       g_mime_part_set_content_encoding (part, GMIME_ENCODING_QUOTED_PRINTABLE);
+               break;
+       case GMIME_CONTENT_ENCODING_8BIT:
+               if (constraint == GMIME_ENCODING_CONSTRAINT_7BIT)
+                       g_mime_part_set_content_encoding (part, encoding);
+               else if (((GMimeFilterBest *) filter)->hadfrom)
+                       g_mime_part_set_content_encoding (part, GMIME_ENCODING_QUOTED_PRINTABLE);
+               break;
+       default:
+               break;
+       }
+       
        g_object_unref (filter);
 }