(compose-gstring-for-terminal): If a character is

not supported by the current terminal, don't make a multi-glyph
grapheme cluster.
(auto-compose-chars): Check font-object by fontp.

1 files changed, 36 insertions, 19 deletions

diff --git a/lisp/composite.el b/lisp/composite.el
index c37a37e18e0..537adab6e90 100644
--- a/lisp/composite.el
+++ b/lisp/composite.el
@@ -664,28 +664,45 @@ a prepending a space before it."
          (nchars (lgstring-char-len gstring))
          (nglyphs (lgstring-glyph-len gstring))
          (i 0)
+         (coding (lgstring-font gstring))
          glyph)
     (while (and (< i nglyphs)
                 (setq glyph (lgstring-glyph gstring i)))
-      (if (= (lglyph-width glyph) 0)
+      (if (not (char-charset (lglyph-char glyph) coding))
           (progn
-            ;; Compose by prepending a space.
-            (setq gstring (lgstring-insert-glyph gstring i (lglyph-copy glyph))
-                  nglyphs (lgstring-glyph-len gstring))
-            (lglyph-set-char (lgstring-glyph gstring i) 32)
-            (setq i (+ 2)))
-        (let ((from (lglyph-from glyph))
-              (to (lglyph-to glyph))
-              (j (1+ i)))
-          (while (and (< j nglyphs)
-                      (setq glyph (lgstring-glyph gstring j))
-                      (= (lglyph-width glyph) 0))
-            (setq to (lglyph-to glyph)
-                  j (1+ j)))
-          (while (< i j)
-            (setq glyph (lgstring-glyph gstring i))
-            (lglyph-set-from-to glyph from to)
-            (setq i (1+ i))))))
+            ;; As the terminal doesn't support this glyph, return a
+            ;; gstring in which each glyph is its own graphme-cluster
+            ;; of width 1..
+            (setq i 0)
+            (while (and (< i nglyphs)
+                        (setq glyph (lgstring-glyph gstring i)))
+              (if (< (lglyph-width glyph) 1)
+                  (lglyph-set-width glyph 1))
+              (lglyph-set-from-to glyph i i)
+              (setq i (1+ i))))
+        (if (= (lglyph-width glyph) 0)
+            (progn
+              ;; Compose by prepending a space.
+              (setq gstring (lgstring-insert-glyph gstring i
+                                                   (lglyph-copy glyph))
+                    nglyphs (lgstring-glyph-len gstring))
+              (setq glyph (lgstring-glyph gstring i))
+              (lglyph-set-char glyph 32)
+              (lglyph-set-width glyph 1)
+              (setq i (+ 2)))
+          (let ((from (lglyph-from glyph))
+                (to (lglyph-to glyph))
+                (j (1+ i)))
+            (while (and (< j nglyphs)
+                        (setq glyph (lgstring-glyph gstring j))
+                        (char-charset (lglyph-char glyph) coding)
+                        (= (lglyph-width glyph) 0))
+              (setq to (lglyph-to glyph)
+                    j (1+ j)))
+            (while (< i j)
+              (setq glyph (lgstring-glyph gstring i))
+              (lglyph-set-from-to glyph from to)
+              (setq i (1+ i)))))))
     gstring))
 
 
@@ -709,7 +726,7 @@ This function is the default value of `auto-composition-function' (which see)."
   (let ((gstring (composition-get-gstring from to font-object string)))
     (if (lgstring-shaped-p gstring)
         gstring
-      (or font-object
+      (or (fontp font-object 'font-object)
           (setq func 'compose-gstring-for-terminal))
       (funcall func gstring))))