Resync fmt_scaled. with OpenBSD.

Fixes underflow reported in bz#3401.

diff --git a/openbsd-compat/fmt_scaled.c b/openbsd-compat/fmt_scaled.c
index 2f76ef931bb1c4fdbc202778fc3f3b4f19760d2f..87d40d2d38c06efd571ace98ec5632a65d8ffc52 100644 (file)
--- a/openbsd-compat/fmt_scaled.c
+++ b/openbsd-compat/fmt_scaled.c
@@ -1,4 +1,4 @@
-/*     $OpenBSD: fmt_scaled.c,v 1.17 2018/05/14 04:39:04 djm Exp $     */
+/*     $OpenBSD: fmt_scaled.c,v 1.21 2022/03/11 07:29:53 dtucker Exp $ */
 
 /*
  * Copyright (c) 2001, 2002, 2003 Ian F. Darwin.  All rights reserved.
@@ -54,9 +54,9 @@ typedef enum {
 } unit_type;
 
 /* These three arrays MUST be in sync!  XXX make a struct */
-static unit_type units[] = { NONE, KILO, MEGA, GIGA, TERA, PETA, EXA };
-static char scale_chars[] = "BKMGTPE";
-static long long scale_factors[] = {
+static const unit_type units[] = { NONE, KILO, MEGA, GIGA, TERA, PETA, EXA };
+static const char scale_chars[] = "BKMGTPE";
+static const long long scale_factors[] = {
        1LL,
        1024LL,
        1024LL*1024,
@@ -153,10 +153,8 @@ scan_scaled(char *scaled, long long *result)
                }
        }
 
-       if (sign) {
+       if (sign)
                whole *= sign;
-               fpart *= sign;
-       }
 
        /* If no scale factor given, we're done. fraction is discarded. */
        if (!*p) {
@@ -191,7 +189,8 @@ scan_scaled(char *scaled, long long *result)
                        /* truncate fpart so it doesn't overflow.
                         * then scale fractional part.
                         */
-                       while (fpart >= LLONG_MAX / scale_fact) {
+                       while (fpart >= LLONG_MAX / scale_fact ||
+                           fpart <= LLONG_MIN / scale_fact) {
                                fpart /= 10;
                                fract_digits--;
                        }
@@ -200,7 +199,10 @@ scan_scaled(char *scaled, long long *result)
                                for (i = 0; i < fract_digits -1; i++)
                                        fpart /= 10;
                        }
-                       whole += fpart;
+                       if (sign == -1)
+                               whole -= fpart;
+                       else
+                               whole += fpart;
                        *result = whole;
                        return 0;
                }
@@ -222,12 +224,16 @@ fmt_scaled(long long number, char *result)
        unsigned int i;
        unit_type unit = NONE;
 
+       /* Not every negative long long has a positive representation. */
+       if (number == LLONG_MIN) {
+               errno = ERANGE;
+               return -1;
+       }
+
        abval = llabs(number);
 
-       /* Not every negative long long has a positive representation.
-        * Also check for numbers that are just too darned big to format
-        */
-       if (abval < 0 || abval / 1024 >= scale_factors[SCALE_LENGTH-1]) {
+       /* Also check for numbers that are just too darned big to format. */
+       if (abval / 1024 >= scale_factors[SCALE_LENGTH-1]) {
                errno = ERANGE;
                return -1;
        }