(print_object): Treat print-length < 0 as nil.

diff --git a/src/print.c b/src/print.c
index be2eee4e5cfd6267b4caf2b6d945b5b87b45b091..80a897fdb2296e5170ed982d1f1de54363491da2 100644 (file)
--- a/src/print.c
+++ b/src/print.c
@@ -1487,12 +1487,17 @@ print_object (obj, printcharfun, escapeflag)
        {
          PRINTCHAR ('(');
          {
-           register int i = 0;
-           register int print_length = 0;
+           int print_length, i;
            Lisp_Object halftail = obj;
 
-           if (INTEGERP (Vprint_length))
-             print_length = XINT (Vprint_length);
+           /* Negative values of print-length are illegal in CL.
+              Treat them like nil, as CMUCL does.  */
+           if (NATNUMP (Vprint_length))
+             print_length = XFASTINT (Vprint_length);
+           else
+             print_length = 0;
+
+           i = 0;
            while (CONSP (obj))
              {
                /* Detect circular list.  */
@@ -1513,7 +1518,8 @@ print_object (obj, printcharfun, escapeflag)
                      {
                        int i;
                        for (i = 0; i < print_number_index; i++)
-                         if (EQ (PRINT_NUMBER_OBJECT (Vprint_number_table, i), obj))
+                         if (EQ (PRINT_NUMBER_OBJECT (Vprint_number_table, i),
+                                 obj))
                            {
                              if (NILP (PRINT_NUMBER_STATUS (Vprint_number_table, i)))
                                {
@@ -1529,24 +1535,31 @@ print_object (obj, printcharfun, escapeflag)
                            }
                      }
                  }
+               
                if (i++)
                  PRINTCHAR (' ');
+               
                if (print_length && i > print_length)
                  {
                    strout ("...", 3, 3, printcharfun, 0);
                    goto end_of_list;
                  }
+               
                print_object (XCAR (obj), printcharfun, escapeflag);
+               
                obj = XCDR (obj);
                if (!(i & 1))
                  halftail = XCDR (halftail);
              }
          }
+
+         /* OBJ non-nil here means it's the end of a dotted list.  */
          if (!NILP (obj))
            {
              strout (" . ", 3, 3, printcharfun, 0);
              print_object (obj, printcharfun, escapeflag);
            }
+         
        end_of_list:
          PRINTCHAR (')');
        }
@@ -1580,10 +1593,12 @@ print_object (obj, printcharfun, escapeflag)
          strout (buf, -1, -1, printcharfun, 0);
          PRINTCHAR ('\"');
 
-         /* Don't print more characters than the specified maximum.  */
-         if (INTEGERP (Vprint_length)
-             && XINT (Vprint_length) < size_in_chars)
-           size_in_chars = XINT (Vprint_length);
+         /* Don't print more characters than the specified maximum.
+            Negative values of print-length are illegal.  Treat them
+            like a print-length of nil.  */
+         if (NATNUMP (Vprint_length)
+             && XFASTINT (Vprint_length) < size_in_chars)
+           size_in_chars = XFASTINT (Vprint_length);
 
          for (i = 0; i < size_in_chars; i++)
            {
@@ -1703,9 +1718,9 @@ print_object (obj, printcharfun, escapeflag)
            register Lisp_Object tem;
 
            /* Don't print more elements than the specified maximum.  */
-           if (INTEGERP (Vprint_length)
-               && XINT (Vprint_length) < size)
-             size = XINT (Vprint_length);
+           if (NATNUMP (Vprint_length)
+               && XFASTINT (Vprint_length) < size)
+             size = XFASTINT (Vprint_length);
 
            for (i = 0; i < size; i++)
              {