1 files changed, 38 insertions, 16 deletions

diff --git a/src/print.c b/src/print.c
index d5ff1be6b31..5d650813458 100644
--- a/src/print.c
+++ b/src/print.c
@@ -216,7 +216,7 @@ int print_output_debug_flag = 1;
    if (MARKERP (printcharfun))						\
      {									\
        EMACS_INT marker_pos;						\
-       if (!(XMARKER (printcharfun)->buffer))				\
+       if (! XMARKER (printcharfun)->buffer)				\
          error ("Marker does not point anywhere");			\
        if (XMARKER (printcharfun)->buffer != current_buffer)		\
          set_buffer_internal (XMARKER (printcharfun)->buffer);		\
@@ -289,7 +289,7 @@ int print_output_debug_flag = 1;
      SET_PT_BOTH (old_point + (old_point >= start_point			\
 			       ? PT - start_point : 0),			\
 		  old_point_byte + (old_point_byte >= start_point_byte	\
-			       ? PT_BYTE - start_point_byte : 0));	\
+				    ? PT_BYTE - start_point_byte : 0));	\
    if (old != current_buffer)						\
      set_buffer_internal (old);
 
@@ -364,7 +364,10 @@ printchar (ch, fun)
    print_buffer.  PRINTCHARFUN t means output to the echo area or to
    stdout if non-interactive.  If neither nil nor t, call Lisp
    function PRINTCHARFUN for each character printed.  MULTIBYTE
-   non-zero means PTR contains multibyte characters.  */
+   non-zero means PTR contains multibyte characters.
+
+   In the case where PRINTCHARFUN is nil, it is safe for PTR to point
+   to data in a Lisp string.  Otherwise that is not safe.  */
 
 static void
 strout (ptr, size, size_byte, printcharfun, multibyte)
@@ -413,7 +416,7 @@ strout (ptr, size, size_byte, printcharfun, multibyte)
       if (size == size_byte)
 	{
 	  for (i = 0; i < size; ++i)
-	    insert_char ((unsigned char )*ptr++);
+	    insert_char ((unsigned char) *ptr++);
 	}
       else
 	{
@@ -497,10 +500,29 @@ print_string (string, printcharfun)
       else
 	chars = SBYTES (string);
 
-      /* strout is safe for output to a frame (echo area) or to print_buffer.  */
-      strout (SDATA (string),
-	      chars, SBYTES (string),
-	      printcharfun, STRING_MULTIBYTE (string));
+      if (EQ (printcharfun, Qt))
+	{
+	  /* Output to echo area.  */
+	  int nbytes = SBYTES (string);
+	  char *buffer;
+
+	  /* Copy the string contents so that relocation of STRING by
+	     GC does not cause trouble.  */
+	  USE_SAFE_ALLOCA;
+
+	  SAFE_ALLOCA (buffer, char *, nbytes);
+	  bcopy (SDATA (string), buffer, nbytes);
+
+	  strout (buffer, chars, SBYTES (string),
+		  printcharfun, STRING_MULTIBYTE (string));
+
+	  SAFE_FREE ();
+	}
+      else
+	/* No need to copy, since output to print_buffer can't GC.  */
+	strout (SDATA (string),
+		chars, SBYTES (string),
+		printcharfun, STRING_MULTIBYTE (string));
     }
   else
     {
@@ -934,7 +956,7 @@ debug_output_compilation_hack (x)
   print_output_debug_flag = x;
 }
 
-#if defined(GNU_LINUX)
+#if defined (GNU_LINUX)
 
 /* This functionality is not vitally important in general, so we rely on
    non-portable ability to use stderr as lvalue.  */
@@ -954,7 +976,7 @@ append to existing target file.  */)
      Lisp_Object file, append;
 {
   if (initial_stderr_stream != NULL)
-    fclose(stderr);
+    fclose (stderr);
   stderr = initial_stderr_stream;
   initial_stderr_stream = NULL;
 
@@ -962,7 +984,7 @@ append to existing target file.  */)
     {
       file = Fexpand_file_name (file, Qnil);
       initial_stderr_stream = stderr;
-      stderr = fopen(SDATA (file), NILP (append) ? "w" : "a");
+      stderr = fopen (SDATA (file), NILP (append) ? "w" : "a");
       if (stderr == NULL)
 	{
 	  stderr = initial_stderr_stream;
@@ -2030,7 +2052,7 @@ print_object (obj, printcharfun, escapeflag)
 	  /* Do you think this is necessary?  */
 	  if (XMARKER (obj)->insertion_type != 0)
 	    strout ("(moves after insertion) ", -1, -1, printcharfun, 0);
-	  if (!(XMARKER (obj)->buffer))
+	  if (! XMARKER (obj)->buffer)
 	    strout ("in no buffer", -1, -1, printcharfun, 0);
 	  else
 	    {
@@ -2044,7 +2066,7 @@ print_object (obj, printcharfun, escapeflag)
 
 	case Lisp_Misc_Overlay:
 	  strout ("#<overlay ", -1, -1, printcharfun, 0);
-	  if (!(XMARKER (OVERLAY_START (obj))->buffer))
+	  if (! XMARKER (OVERLAY_START (obj))->buffer)
 	    strout ("in no buffer", -1, -1, printcharfun, 0);
 	  else
 	    {
@@ -2091,8 +2113,8 @@ print_object (obj, printcharfun, escapeflag)
 
 	case Lisp_Misc_Kboard_Objfwd:
 	  strout ("#<kboard_objfwd to ", -1, -1, printcharfun, 0);
-	  print_object (*(Lisp_Object *)((char *) current_kboard
-					 + XKBOARD_OBJFWD (obj)->offset),
+	  print_object (*(Lisp_Object *) ((char *) current_kboard
+					  + XKBOARD_OBJFWD (obj)->offset),
 			printcharfun, escapeflag);
 	  PRINTCHAR ('>');
 	  break;
@@ -2178,7 +2200,7 @@ print_interval (interval, printcharfun)
   print_object (make_number (interval->position), printcharfun, 1);
   PRINTCHAR (' ');
   print_object (make_number (interval->position + LENGTH (interval)),
-	 printcharfun, 1);
+		printcharfun, 1);
   PRINTCHAR (' ');
   print_object (interval->plist, printcharfun, 1);
 }