(Fcall_process): Simplify handling of display arg.

Resume `display_on_the_fly' once a coding system is determined.

1 files changed, 14 insertions, 6 deletions

diff --git a/src/callproc.c b/src/callproc.c
index effd7ecbb14..5d7447d94f2 100644
--- 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;