num conversions: allow for leading '+' (renice needs that)

1 files changed, 7 insertions, 5 deletions

diff --git a/libbb/xatonum_template.c b/libbb/xatonum_template.c
index 205da53c8..9f9dc1102 100644
--- a/libbb/xatonum_template.c
+++ b/libbb/xatonum_template.c
@@ -21,9 +21,8 @@ unsigned type xstrtou(_range_sfx)(const char *numstr, int base,
         int old_errno;
         char *e;
 
-        /* Disallow '-' and any leading whitespace.  Speed isn't critical here
-         * since we're parsing commandline args.  So make sure we get the
-         * actual isspace function rather than a lnumstrer macro implementaion. */
+        /* Disallow '-' and any leading whitespace. Make sure we get the
+         * actual isspace function rather than a macro implementaion. */
         if (*numstr == '-' || *numstr == '+' || (isspace)(*numstr))
                 goto inval;
 
@@ -127,9 +126,12 @@ type xstrto(_range_sfx)(const char *numstr, int base,
         type r;
         const char *p = numstr;
 
-        if (p[0] == '-') {
+        /* NB: if you'll decide to disallow '+':
+         * at least renice applet needs to allow it */
+        if (p[0] == '+' || p[0] == '-') {
                 ++p;
-                ++u;    /* two's complement */
+                if (p[0] == '-')
+                        ++u; /* = <type>_MIN (01111... + 1 == 10000...) */
         }
 
         r = xstrtou(_range_sfx)(p, base, 0, u, suffixes);