user32: LoadString should use only 16 bits of string id

[Andrey Turkin]

String resource id is unsigned short (16 bits), and tests show that 
native implementation of LoadString treat it as such (that is, only 16 
lowest bits are used). Wine's implementation used 20 bits; this patch 
forces it to use 16 bits, and adds few tests for this case.

ChangeLog:

Use only 16 lowest bits of string id in LoadString
-------------- next part --------------
diff -aurp wine-0.9.21/dlls/user/resource.c wine-0.9.21-my/dlls/user/resource.c
--- wine-0.9.21/dlls/user/resource.c	2006-09-13 23:10:25.000000000 +0400
+++ wine-0.9.21-my/dlls/user/resource.c	2006-09-22 05:14:23.000000000 +0400
@@ -369,9 +369,9 @@ INT WINAPI LoadStringW( HINSTANCE instan
     TRACE("instance = %p, id = %04x, buffer = %p, length = %d\n",
           instance, resource_id, buffer, buflen);
 
-    /* Use bits 4 - 19 (incremented by 1) as resourceid, mask out
-     * 20 - 31. */
-    hrsrc = FindResourceW( instance, MAKEINTRESOURCEW(((resource_id>>4)&0xffff)+1),
+    /* Use bits 4 - 15 (incremented by 1) as resourceid, mask out
+     * 16 - 31. */
+    hrsrc = FindResourceW( instance, MAKEINTRESOURCEW(((resource_id>>4)&0xfff)+1),
                            (LPWSTR)RT_STRING );
     if (!hrsrc) return 0;
     hmem = LoadResource( instance, hrsrc );
diff -aurp wine-0.9.21/dlls/user/tests/resource.c wine-0.9.21-my/dlls/user/tests/resource.c
--- wine-0.9.21/dlls/user/tests/resource.c	2006-09-13 23:10:25.000000000 +0400
+++ wine-0.9.21-my/dlls/user/tests/resource.c	2006-09-22 05:08:11.000000000 +0400
@@ -61,6 +61,11 @@ static void test_LoadStringA (void)
         ok (buf[len] == 0, "bufsiz=%d: NUL termination missing\n",
             bufsiz);
     }
+
+    ok (LoadStringA (hInst, 0x00010000, buf, sizeof(buf)) > 0, "LoadString failed\n");
+    ok (LoadStringA (hInst, 0x80000000, buf, sizeof(buf)) > 0, "LoadString failed\n");
+    ok (LoadStringA (hInst, 0x80130000, buf, sizeof(buf)) > 0, "LoadString failed\n");
+    ok (LoadStringA (hInst, 0xFFFF0000, buf, sizeof(buf)) > 0, "LoadString failed\n");
 }
 
 static void test_accel1(void)