Improve comments for last change.

1 files changed, 2 insertions, 1 deletions

diff --git a/src/w32font.c b/src/w32font.c
index 65e6c5448a6..4492a275bd1 100644
--- a/src/w32font.c
+++ b/src/w32font.c
@@ -1407,7 +1407,8 @@ add_font_entity_to_list (logical_font, physical_font, font_type, lParam)
               && logical_font->elfLogFont.lfCharSet != DEFAULT_CHARSET
               && logical_font->elfLogFont.lfCharSet != ANSI_CHARSET)
             return 1;
-          /* unicode-sip fonts must contain characters beyond the BMP.  */
+          /* unicode-sip fonts must contain characters beyond the BMP,
+             so look for bit 57 (surrogates) in the Unicode subranges.  */
           else if (EQ (spec_charset, Qunicode_sip)
                    && !(physical_font->ntmFontSig.fsUsb[1] & 0x02000000))
             return 1;