msvcrt: Interpret 'I' as size_t size specifier for integer conversions.

dlls/msvcrt/printf.h

@@ -34,7 +34,7 @@ typedef struct FUNC_NAME(pf_flags_t)
 {
     APICHAR Sign, LeftAlign, Alternate, PadZero;
     int FieldLength, Precision;
-    APICHAR IntegerLength, IntegerDouble;
+    APICHAR IntegerLength, IntegerDouble, IntegerNative;
     APICHAR WideString;
     APICHAR Format;
 } FUNC_NAME(pf_flags);
@@ -470,7 +470,7 @@ int FUNC_NAME(pf_printf)(FUNC_NAME(puts_clbk) pf_puts, void *puts_ctx, const API
                 else if(isdigit(*(p+1)) || !*(p+1))
                     break;
                 else
-                    p++;
+                    flags.IntegerNative = *p++;
             } else if(*p == 'w')
                 flags.WideString = *p++;
             else if((*p == 'F' || *p == 'N') && legacy_msvcrt_compat)
@@ -533,7 +533,7 @@ int FUNC_NAME(pf_printf)(FUNC_NAME(puts_clbk) pf_puts, void *puts_ctx, const API
             if(!tmp)
                 return -1;
 
-            if(flags.IntegerDouble)
+            if(flags.IntegerDouble || (flags.IntegerNative && sizeof(void*) == 8))
                 FUNC_NAME(pf_integer_conv)(tmp, max_len, &flags, pf_args(args_ctx, pos,
                             VT_I8, valist).get_longlong);
             else if(flags.Format=='d' || flags.Format=='i')

dlls/msvcrt/tests/printf.c

@@ -422,6 +422,11 @@ static void test_sprintf( void )
         r = sprintf(buffer,format,(void *)57);
         ok(!strcmp(buffer,"0X0000000000000039  "),"Pointer formatted incorrectly\n");
         ok( r==20, "return count wrong\n");
+
+        format = "%Ix %d";
+        r = sprintf(buffer,format,(size_t)0x12345678123456,1);
+        ok(!strcmp(buffer,"12345678123456 1"),"buffer = %s\n",buffer);
+        ok( r==16, "return count wrong\n");
     }
     else
     {
@@ -449,6 +454,11 @@ static void test_sprintf( void )
         r = sprintf(buffer,format,(void *)57);
         ok(!strcmp(buffer,"0X00000039  "),"Pointer formatted incorrectly\n");
         ok( r==12, "return count wrong\n");
+
+        format = "%Ix %d";
+        r = sprintf(buffer,format,0x123456,1);
+        ok(!strcmp(buffer,"123456 1"),"buffer = %s\n",buffer);
+        ok( r==8, "return count wrong\n");
     }
 
     format = "%04s";