[glib] win32_strftime_helper: Factor out the common code

[Philip Withnall <pwithnall src gnome org>]

commit 5520a879303264c57757b1fb806b9fe720cac664
Author: Rafal Luzynski <digitalfreak lingonborough com>
Date:   Fri Feb 16 22:20:50 2018 +0100

    win32_strftime_helper: Factor out the common code
    
    Factor out the common code supporting "%B", "%b", and "%h" format
    specifiers. It will be helpful for the next commit.
    
    https://bugzilla.gnome.org/show_bug.cgi?id=749206

 glib/gdate.c | 27 +++++++++++++++++++--------
 1 file changed, 19 insertions(+), 8 deletions(-)
---
diff --git a/glib/gdate.c b/glib/gdate.c
index 252cb6748..fd5e5444d 100644
--- a/glib/gdate.c
+++ b/glib/gdate.c
@@ -2133,6 +2133,23 @@ g_date_order (GDate *date1,
 }
 
 #ifdef G_OS_WIN32
+static void
+append_month_name (GArray     *result,
+                  LCID        lcid,
+                  SYSTEMTIME *systemtime,
+                  gboolean    abbreviated)
+{
+  int n;
+  WORD base;
+
+  base = abbreviated ? LOCALE_SABBREVMONTHNAME1 : LOCALE_SMONTHNAME1;
+  n = GetLocaleInfoW (lcid, base + systemtime->wMonth - 1, NULL, 0);
+  g_array_set_size (result, result->len + n);
+  GetLocaleInfoW (lcid, base + systemtime->wMonth - 1,
+                 ((wchar_t *) result->data) + result->len - n, n);
+  g_array_set_size (result, result->len - 1);
+}
+
 static gsize
 win32_strftime_helper (const GDate     *d,
                       const gchar     *format,
@@ -2219,16 +2236,10 @@ win32_strftime_helper (const GDate     *d,
              break;
            case 'b':
            case 'h':
-             n = GetLocaleInfoW (lcid, LOCALE_SABBREVMONTHNAME1+systemtime.wMonth-1, NULL, 0);
-             g_array_set_size (result, result->len + n);
-             GetLocaleInfoW (lcid, LOCALE_SABBREVMONTHNAME1+systemtime.wMonth-1, ((wchar_t *) result->data) 
+ result->len - n, n);
-             g_array_set_size (result, result->len - 1);
+             append_month_name (result, lcid, &systemtime, TRUE);
              break;
            case 'B':
-             n = GetLocaleInfoW (lcid, LOCALE_SMONTHNAME1+systemtime.wMonth-1, NULL, 0);
-             g_array_set_size (result, result->len + n);
-             GetLocaleInfoW (lcid, LOCALE_SMONTHNAME1+systemtime.wMonth-1, ((wchar_t *) result->data) + 
result->len - n, n);
-             g_array_set_size (result, result->len - 1);
+             append_month_name (result, lcid, &systemtime, FALSE);
              break;
            case 'c':
              n = GetDateFormatW (lcid, 0, &systemtime, NULL, NULL, 0);