msvcrt: Cache locale string to LCID conversion results.

dlls/msvcrt/locale.c

@@ -217,10 +217,17 @@ extern int atoi(const char *);
 /* Internal: Find the LCID for a locale specification */
 LCID MSVCRT_locale_to_LCID(const char *locale, unsigned short *codepage)
 {
+    thread_data_t *data = msvcrt_get_thread_data();
     LCID lcid;
     locale_search_t search;
     const char *cp, *region;
 
+    if (!strcmp(locale, data->cached_locale)) {
+        if (codepage)
+            *codepage = data->cached_cp;
+        return data->cached_lcid;
+    }
+
     memset(&search, 0, sizeof(locale_search_t));
 
     cp = strchr(locale, '.');
@@ -292,6 +299,12 @@ LCID MSVCRT_locale_to_LCID(const char *locale, unsigned short *codepage)
     if (codepage)
         *codepage = atoi(search.found_codepage);
 
+    if (strlen(locale) < sizeof(data->cached_locale)) {
+        strcpy(data->cached_locale, locale);
+        data->cached_lcid = lcid;
+        data->cached_cp = codepage ? *codepage : atoi(search.found_codepage);
+    }
+
     return lcid;
 }
 

dlls/msvcrt/msvcrt.h

@@ -237,7 +237,12 @@ struct __thread_data {
     void                           *unk6[3];
     int                             unk7;
     EXCEPTION_RECORD               *exc_record;
-    void                           *unk8[100];
+    void                           *unk8[7];
+    LCID                            cached_lcid;
+    int                             unk9[3];
+    DWORD                           cached_cp;
+    char                            cached_locale[131];
+    void                           *unk10[100];
 };
 
 typedef struct __thread_data thread_data_t;