strftime: Pass the additional flags from "%EY" to "%Ey" [BZ #24096]

The full representation of the alternative calendar year (%EY)
typically includes an internal use of "%Ey".  As a GNU extension,
apply any flags on "%EY" (e.g. "%_EY", "%-EY") to the internal "%Ey",
allowing users of "%EY" to control how the year is padded.

Reviewed-by: Rafal Luzynski <digitalfreak@lingonborough.com>
Reviewed-by: Zack Weinberg <zackw@panix.com>

ChangeLog:

	[BZ #24096]
	* manual/time.texi (strftime): Document "%EC" and "%EY".
	* time/Makefile (tests): Add tst-strftime2.
	(LOCALES): Add ja_JP.UTF-8, lo_LA.UTF-8, and th_TH.UTF-8.
	* time/strftime_l.c (__strftime_internal): Add argument yr_spec to
	override padding for "%Ey".
	If an optional flag ('_' or '-') is specified to "%EY", interpret the
	"%Ey" in the subformat as if decorated with that flag.
	* time/tst-strftime2.c: New file.

1 files changed, 10 insertions, 0 deletions

diff --git a/ChangeLog b/ChangeLog
index 64ed089867..8f3924d742 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -5,6 +5,16 @@
 	* time/strftime_l.c (__strftime_internal): Set the default width
 	padding with zero of "%Ey" to 2.
 
+	[BZ #24096]
+	* manual/time.texi (strftime): Document "%EC" and "%EY".
+	* time/Makefile (tests): Add tst-strftime2.
+	(LOCALES): Add ja_JP.UTF-8, lo_LA.UTF-8, and th_TH.UTF-8.
+	* time/strftime_l.c (__strftime_internal): Add argument yr_spec to
+	override padding for "%Ey".
+	If an optional flag ('_' or '-') is specified to "%EY", interpret the
+	"%Ey" in the subformat as if decorated with that flag.
+	* time/tst-strftime2.c: New file.
+
 2019-01-24  Adhemerval Zanella  <adhemerval.zanella@linaro.org>
 
 	* support/xsigstack.c (MAP_NORESERVE, MAP_STACK): Define if they