bin/59749: awk bad test to see if printf supports the %a format

[trevor.zacks%btopenworld.com@localhost]

>Number:         59749
>Category:       bin
>Synopsis:       awk bad test to see if printf supports the %a format
>Confidential:   no
>Severity:       non-critical
>Priority:       low
>Responsible:    bin-bug-people
>State:          open
>Class:          sw-bug
>Submitter-Id:   net
>Arrival-Date:   Thu Nov 06 13:35:00 +0000 2025
>Originator:     Trevor Zacks
>Release:        netbsd 10.1
>Organization:
>Environment:
>Description:
usr/src/external/historical/nawk/dist/run.c

int format(char **pbuf, int *pbufsize, const char *s, Node *a)  /* printf-like conversions */
{
 . . . . . .
        if (first) {
                char xbuf[100];

                snprintf(xbuf, sizeof(xbuf), "%a", 42.0);
                have_a_format = (strcmp(xbuf, "0x1.5p+5") == 0);
                first = false;
        }

Will never match "0x1.5p+5" unless the default printf() precision is 1

>How-To-Repeat:

>Fix:
change

snprintf(xbuf, sizeof(xbuf), "%a", 42.0);

to

snprintf(xbuf, sizeof(xbuf), "%.1a", 42.0);

or just check for "0x" as does GNU