Allow minibuffer default to be a list of default values.

With empty input use the first element of this list as returned default.
(string_to_object):
(read_minibuf_noninteractive):  If defalt is cons, set val to its car.
(read_minibuf): If defalt is cons, set histstring to its car.
(Fread_string): If default_value is cons, set val to its car.
(Fread_buffer): If def is cons, use its car.
(Fcompleting_read): If defalt is cons, set val to its car.

2 files changed, 24 insertions, 7 deletions

diff --git a/src/ChangeLog b/src/ChangeLog
index 3df88c6f332..1ed1d3a5d38 100644
--- a/src/ChangeLog
+++ b/src/ChangeLog
@@ -1,3 +1,14 @@
+2007-10-22  Juri Linkov  <juri@jurta.org>
+
+        * minibuf.c: Allow minibuffer default to be a list of default values.
+        With empty input use the first element of this list as returned default.
+        (string_to_object):
+        (read_minibuf_noninteractive):  If defalt is cons, set val to its car.
+        (read_minibuf): If defalt is cons, set histstring to its car.
+        (Fread_string): If default_value is cons, set val to its car.
+        (Fread_buffer): If def is cons, use its car.
+        (Fcompleting_read): If defalt is cons, set val to its car.
+
 2007-10-21  Michael Albinus  <michael.albinus@gmx.de>
 
         * fileio.c (Fcopy_file): Call file name handler with preserve_uid_gid.
diff --git a/src/minibuf.c b/src/minibuf.c
index d3c9eb505b6..377968fab4f 100644
--- a/src/minibuf.c
+++ b/src/minibuf.c
@@ -257,9 +257,13 @@ string_to_object (val, defalt)
 
   GCPRO2 (val, defalt);
 
-  if (STRINGP (val) && SCHARS (val) == 0
-      && STRINGP (defalt))
-    val = defalt;
+  if (STRINGP (val) && SCHARS (val) == 0)
+    {
+      if (STRINGP (defalt))
+        val = defalt;
+      else if (CONSP (defalt) && STRINGP (XCAR (defalt)))
+        val = XCAR (defalt);
+    }
 
   expr_and_pos = Fread_from_string (val, Qnil, Qnil);
   pos = XINT (Fcdr (expr_and_pos));
@@ -337,7 +341,7 @@ read_minibuf_noninteractive (map, initial, prompt, backup_n, expflag,
 
   /* If Lisp form desired instead of string, parse it. */
   if (expflag)
-    val = string_to_object (val, defalt);
+    val = string_to_object (val, CONSP (defalt) ? XCAR (defalt) : defalt);
 
   return val;
 }
@@ -785,6 +789,8 @@ read_minibuf (map, initial, prompt, backup_n, expflag,
     histstring = val;
   else if (STRINGP (defalt))
     histstring = defalt;
+  else if (CONSP (defalt) && STRINGP (XCAR (defalt)))
+    histstring = XCAR (defalt);
   else
     histstring = Qnil;
 
@@ -1102,7 +1108,7 @@ Fifth arg INHERIT-INPUT-METHOD, if non-nil, means the minibuffer inherits
                                Qnil, history, default_value,
                                inherit_input_method);
   if (STRINGP (val) && SCHARS (val) == 0 && ! NILP (default_value))
-    val = default_value;
+    val = CONSP (default_value) ? XCAR (default_value) : default_value;
   return val;
 }
 
@@ -1225,7 +1231,7 @@ The argument PROMPT should be a string ending with a colon and a space.  */)
 
           args[0] = build_string ("%s (default %s): ");
           args[1] = prompt;
-          args[2] = def;
+          args[2] = CONSP (def) ? XCAR (def) : def;
           prompt = Fformat (3, args);
         }
 
@@ -1835,7 +1841,7 @@ Completion ignores case if the ambient value of
                       !NILP (inherit_input_method));
 
   if (STRINGP (val) && SCHARS (val) == 0 && ! NILP (def))
-    val = def;
+    val = CONSP (def) ? XCAR (def) : def;
 
   RETURN_UNGCPRO (unbind_to (count, val));
 }