[PATCH v2 1/1] kernelbase: Fix grouping repeat for number formatting.

[Gabriel Ivăncescu]

From: Gabriel Ivăncescu

Fixes a regression introduced by 56099a31242dcc522fb94643e70553e152c522ec.

LOCALE_SGROUPING's string and the `Grouping` field in NUMBERFMTW are
confusingly different. The former, which is what is fixed here, treats a '0'
as a repeat of the previous grouping. But a 0 at the end of the `Grouping`
field prevents it from repeating (it repeats by default otherwise) so
it's the opposite. Note that without a '0' in the LOCALE_SGROUPING string,
it shouldn't even repeat in the first place.

This fixes the typical "3;0" default grouping, for example.

Signed-off-by: Gabriel Ivăncescu 
---
 dlls/kernelbase/locale.c | 30 +++++++++++++++++++++++++-----
 1 file changed, 25 insertions(+), 5 deletions(-)

diff --git a/dlls/kernelbase/locale.c b/dlls/kernelbase/locale.c
index 1e96e49622e..cb1b460090d 100644
--- a/dlls/kernelbase/locale.c
+++ b/dlls/kernelbase/locale.c
@@ -7245,11 +7245,16 @@ BOOL WINAPI SetUserGeoName(PWSTR geo_name)

static void grouping_to_string( UINT grouping, WCHAR *buffer )
 {
+    UINT last_digit = grouping % 10;
     WCHAR tmp[10], *p = tmp;

+    /* The string is confusingly different when it comes to repetitions (trailing zeros). For a string,
+     * a 0 signals that the format needs to be repeat, which is the opposite of the grouping integer. */
     while (grouping)
     {
-        *p++ = '0' + grouping % 10;
+        UINT digit = grouping % 10;
+        if (digit)
+            *p++ = '0' + digit;
         grouping /= 10;
     }
     while (p > tmp)
@@ -7257,6 +7262,11 @@ static void grouping_to_string( UINT grouping, WCHAR *buffer )
         *buffer++ = *(--p);
         if (p > tmp) *buffer++ = ';';
     }
+    if (last_digit != 0)
+    {
+        *buffer++ = ';';
+        *buffer++ = '0';
+    }
     *buffer = 0;
 }

@@ -7272,9 +7282,9 @@ static WCHAR *prepend_str( WCHAR *end, const WCHAR *str )
 static WCHAR *format_number( WCHAR *end, const WCHAR *value, const WCHAR *decimal_sep,
                              const WCHAR *thousand_sep, const WCHAR *grouping, UINT digits, BOOL lzero )
 {
+    UINT i, len = 0, limit = ~0, repeat = ~0;
     const WCHAR *frac = NULL;
     BOOL round = FALSE;
-    UINT i, len = 0;

*(--end) = 0;

@@ -7327,9 +7337,10 @@ static WCHAR *format_number( WCHAR *end, const WCHAR *value, const WCHAR *decima
     }
     if (len) lzero = FALSE;

+    if (*grouping >= '1' && *grouping <= '9')
+        limit = repeat = *grouping - '0';
     while (len)
     {
-        UINT limit = *grouping == '0' ? ~0u : *grouping - '0';
         while (len && limit--)
         {
             WCHAR ch = value[--len];
@@ -7345,7 +7356,16 @@ static WCHAR *format_number( WCHAR *end, const WCHAR *value, const WCHAR *decima
             *(--end) = ch;
         }
         if (len) end = prepend_str( end, thousand_sep );
-        if (grouping[1] == ';') grouping += 2;
+        if (*grouping == '0')
+            limit = repeat;
+        else if (grouping[1] == ';')
+        {
+            grouping += 2;
+            if (*grouping == '0')
+                limit = repeat;
+            else if (*grouping >= '1' && *grouping <= '9')
+                limit = repeat = *grouping - '0';
+        }
     }
     if (round) *(--end) = '1';
     else if (lzero) *(--end) = '0';
@@ -7356,7 +7376,7 @@ static WCHAR *format_number( WCHAR *end, const WCHAR *value, const WCHAR *decima
 static int get_number_format( const NLS_LOCALE_DATA *locale, DWORD flags, const WCHAR *value,
                               const NUMBERFMTW *format, WCHAR *buffer, int len )
 {
-    WCHAR *num, fmt_decimal[4], fmt_thousand[4], fmt_neg[5], grouping[20], output[256];
+    WCHAR *num, fmt_decimal[4], fmt_thousand[4], fmt_neg[5], grouping[22], output[256];
     const WCHAR *decimal_sep = fmt_decimal, *thousand_sep = fmt_thousand;
     DWORD digits, lzero, order;
     int ret = 0;