Add collation versions for Windows.

On Vista and later, use GetNLSVersionEx() to request collation version
information.

Reviewed-by: Juan José Santamaría Flecha <juanjo.santamaria@gmail.com>
Discussion: https://postgr.es/m/CA%2BhUKGJvqup3s%2BJowVTcacZADO6dOhfdBmvOPHLS3KXUJu41Jw%40mail.gmail.com

diff --git a/src/backend/utils/adt/pg_locale.c b/src/backend/utils/adt/pg_locale.c
index b42122f9ceaf22cd966af93d4c3831d106767b34..2562eb5416df081bbcbc82e913dcd7b88b375bd7 100644 (file)
--- a/src/backend/utils/adt/pg_locale.c
+++ b/src/backend/utils/adt/pg_locale.c
@@ -1555,6 +1555,33 @@ get_collation_actual_version(char collprovider, const char *collcollate)
 
        /* Use the glibc version because we don't have anything better. */
        collversion = pstrdup(gnu_get_libc_version());
+#elif defined(WIN32) && _WIN32_WINNT >= 0x0600
+       /*
+        * If we are targeting Windows Vista and above, we can ask for a name
+        * given a collation name (earlier versions required a location code
+        * that we don't have).
+        */
+       NLSVERSIONINFOEX version = {sizeof(NLSVERSIONINFOEX)};
+       WCHAR       wide_collcollate[LOCALE_NAME_MAX_LENGTH];
+
+       /* These would be invalid arguments, but have no version. */
+       if (pg_strcasecmp("c", collcollate) == 0 ||
+           pg_strcasecmp("posix", collcollate) == 0)
+           return NULL;
+
+       /* For all other names, ask the OS. */
+       MultiByteToWideChar(CP_ACP, 0, collcollate, -1, wide_collcollate,
+                           LOCALE_NAME_MAX_LENGTH);
+       if (!GetNLSVersionEx(COMPARE_STRING, wide_collcollate, &version))
+           ereport(ERROR,
+                   (errmsg("could not get collation version for locale \"%s\": error code %lu",
+                           collcollate,
+                           GetLastError())));
+       collversion = psprintf("%d.%d,%d.%d",
+                              (version.dwNLSVersion >> 8) & 0xFFFF,
+                              version.dwNLSVersion & 0xFF,
+                              (version.dwDefinedVersion >> 8) & 0xFFFF,
+                              version.dwDefinedVersion & 0xFF);
 #endif
    }