Allow Zs characters to be composed

* src/composite.c (char_composable_p): Allow SPC and other Zs
characters to be composed.

* lisp/composite.el (compose-gstring-for-graphic): Don't
reject characters whose general category is Zs.  (Bug#14461)

2 files changed, 6 insertions, 5 deletions

diff --git a/lisp/composite.el b/lisp/composite.el
index d0f20949438..b3661cc2fa0 100644
--- a/lisp/composite.el
+++ b/lisp/composite.el
@@ -558,9 +558,9 @@ All non-spacing characters have this function in
             ;; "Improper" base characters are of the following general
             ;; categories:
             ;;   Mark (nonspacing, combining, enclosing)
-            ;;   Separator (space, line, paragraph)
+            ;;   Separator (line, paragraph)
             ;;   Other (control, format, surrogate)
-            '(Mn Mc Me Zs Zl Zp Cc Cf Cs))
+            '(Mn Mc Me Zl Zp Cc Cf Cs))
       nil)
 
      ;; A base character and the following non-spacing characters.
diff --git a/src/composite.c b/src/composite.c
index a6606d5fc45..efbd055cef2 100644
--- a/src/composite.c
+++ b/src/composite.c
@@ -919,16 +919,17 @@ autocmp_chars (Lisp_Object rule, ptrdiff_t charpos, ptrdiff_t bytepos,
 }
 
 /* 1 iff the character C is composable.  Characters of general
-   category Z? or C? are not composable except for ZWNJ and ZWJ. */
+   category Z? or C? are not composable except for ZWNJ and ZWJ,
+   and characters of category Zs. */
 
 static bool
 char_composable_p (int c)
 {
   Lisp_Object val;
-  return (c > ' '
+  return (c >= ' '
           && (c == ZERO_WIDTH_NON_JOINER || c == ZERO_WIDTH_JOINER
               || (val = CHAR_TABLE_REF (Vunicode_category_table, c),
-                  (FIXNUMP (val) && (XFIXNUM (val) <= UNICODE_CATEGORY_So)))));
+                  (FIXNUMP (val) && (XFIXNUM (val) <= UNICODE_CATEGORY_Zs)))));
 }
 
 /* Update cmp_it->stop_pos to the next position after CHARPOS (and