(Finternal_set_lisp_face_attribute): Make null values of :foreground

and :background equivalent to unspecified (20.x compatibility).

1 files changed, 6 insertions, 0 deletions

diff --git a/src/xfaces.c b/src/xfaces.c
index 11e2c3c10b7..68d63d690d9 100644
--- a/src/xfaces.c
+++ b/src/xfaces.c
@@ -3217,6 +3217,9 @@ FRAME 0 means change the face on all frames, and change the default
     }
   else if (EQ (attr, QCforeground))
     {
+      /* Compatibility with 20.x.  */
+      if (NILP (value))
+        value = Qunspecified;
       if (!UNSPECIFIEDP (value) && !IGNORE_DEFFACE_P (value))
         {
           /* Don't check for valid color names here because it depends
@@ -3231,6 +3234,9 @@ FRAME 0 means change the face on all frames, and change the default
     }
   else if (EQ (attr, QCbackground))
     {
+      /* Compatibility with 20.x.  */
+      if (NILP (value))
+        value = Qunspecified;
       if (!UNSPECIFIEDP (value) && !IGNORE_DEFFACE_P (value))
         {
           /* Don't check for valid color names here because it depends