(Fcall_process): Simplify handling of display arg.

Resume `display_on_the_fly' once a coding system is determined.

diff --git a/src/callproc.c b/src/callproc.c
index effd7ecbb14db8fec548a3519429d3fccaf18bfc..5d7447d94f28a1a594b9b440d9df59eb452d2673 100644 (file)
--- a/src/callproc.c
+++ b/src/callproc.c
@@ -216,7 +216,8 @@ usage: (call-process PROGRAM &optional INFILE BUFFER DISPLAY &rest ARGS)  */)
      int nargs;
      register Lisp_Object *args;
 {
-  Lisp_Object infile, buffer, current_dir, display, path;
+  Lisp_Object infile, buffer, current_dir, path;
+  int display_p;
   int fd[2];
   int filefd;
   register int pid;
@@ -372,7 +373,7 @@ usage: (call-process PROGRAM &optional INFILE BUFFER DISPLAY &rest ARGS)  */)
     UNGCPRO;
   }
 
-  display = nargs >= 4 ? args[3] : Qnil;
+  display_p = INTERACTIVE && nargs >= 4 && !NILP (args[3]);
 
   filefd = emacs_open (SDATA (infile), O_RDONLY, 0);
   if (filefd < 0)
@@ -747,7 +748,7 @@ usage: (call-process PROGRAM &optional INFILE BUFFER DISPLAY &rest ARGS)  */)
     int first = 1;
     int total_read = 0;
     int carryover = 0;
-    int display_on_the_fly = !NILP (display) && INTERACTIVE;
+    int display_on_the_fly = display_p;
     struct coding_system saved_coding;
     int pt_orig = PT, pt_byte_orig = PT_BYTE;
     int inserted;
@@ -823,12 +824,15 @@ usage: (call-process PROGRAM &optional INFILE BUFFER DISPLAY &rest ARGS)  */)
                  {
                    /* We have detected some coding system.  But,
                       there's a possibility that the detection was
-                      done by insufficient data.  So, we give up
-                      displaying on the fly.  */
+                      done by insufficient data.  So, we try the code
+                      detection again with more data.  */
                    xfree (decoding_buf);
                    display_on_the_fly = 0;
                    process_coding = saved_coding;
                    carryover = nread;
+                   /* This is to make the above condition always
+                      fails in the future.  */
+                   saved_coding.type = coding_type_no_conversion;
                    continue;
                  }
 
@@ -929,12 +933,16 @@ usage: (call-process PROGRAM &optional INFILE BUFFER DISPLAY &rest ARGS)  */)
            bufptr = tempptr;
          }
 
-       if (!NILP (display) && INTERACTIVE)
+       if (display_p)
          {
            if (first)
              prepare_menu_bars ();
            first = 0;
            redisplay_preserve_echo_area (1);
+           /* This variable might have been set to 0 for code
+              detection.  In that case, we set it back to 1 because
+              we should have already detected a coding system.  */
+           display_on_the_fly = 1;
          }
        immediate_quit = 1;
        QUIT;