git: 40a925385fa6 - stable/12 - awk: revert upstream's attempt to disallow hex strings

[Warner Losh]

The branch stable/12 has been updated by imp:

URL: https://cgit.FreeBSD.org/src/commit/?id=40a925385fa6b7c1a177880e36aa0fc278043e49

commit 40a925385fa6b7c1a177880e36aa0fc278043e49
Author:     Warner Losh <imp at FreeBSD.org>
AuthorDate: 2021-07-15 22:46:06 +0000
Commit:     Warner Losh <imp at FreeBSD.org>
CommitDate: 2021-07-15 23:27:57 +0000

    awk: revert upstream's attempt to disallow hex strings
    
    Upstream one-true-awk decided to disallow hex strings as numbers. This
    is in line with awk's behavior prior to C99, and allowed by the POSIX
    standard. The standard, however, allows them to be treated as numbers
    because that's what the standard said in the 2001 through 2004 editions.
    Since 2001, the nawk in FreeBSD has treated them as numbers, so restore
    that behavior, allowed by the standard.
    
    A number of scripts in the FreeBSD tree depend on this interpretation,
    including scripts to build the kernel which had mysteriously started
    failing for some people and not others. By re-allowing 0x hex numbers,
    this fixes those scripts and restores POLA.
    
    Upstream issue:         https://github.com/onetrueawk/awk/issues/126
    Sponsored by:           Netflix
    Reviewed by:            kevans
    MFC After:              asap due to regression alrady merged to stable
    Differential Revision:  https://reviews.freebsd.org/D31199
    
    (cherry picked from commit d4d252c49976de33d0a2926df733744d0b8d95fa)
---
 contrib/one-true-awk/lib.c | 9 +++++++++
 1 file changed, 9 insertions(+)

diff --git a/contrib/one-true-awk/lib.c b/contrib/one-true-awk/lib.c
index 18adbd2d1fd6..6bfe5e8eaad9 100644
--- a/contrib/one-true-awk/lib.c
+++ b/contrib/one-true-awk/lib.c
@@ -793,9 +793,18 @@ bool is_valid_number(const char *s, bool trailing_stuff_ok,
 	while (isspace(*s))
 		s++;
 
+/*
+ * This test, while allowed by newer POSIX standards, represents a regression
+ * where hex strings were treated as numbers in nawk the whole time it has been
+ * in FreeBSD (since 2001). The POSIX 2001 through 2004 standards mandated this
+ * behavior and the current standard allows it. Deviate from upstream by restoring
+ * the prior FreeBSD behavior.
+ */
+#if 0
 	// no hex floating point, sorry
 	if (s[0] == '0' && tolower(s[1]) == 'x')
 		return false;
+#endif
 
 	// allow +nan, -nan, +inf, -inf, any other letter, no
 	if (s[0] == '+' || s[0] == '-') {