Test UTF-8 decoding

This creates a unit test for cm_utf8.  See issue #10003.

Tests/CMakeLib/CMakeLists.txt

@@ -5,6 +5,7 @@ include_directories(
   )
 
 set(CMakeLib_TESTS
+  testUTF8
   testXMLParser
   )
 

Tests/CMakeLib/testUTF8.cxx

@@ -0,0 +1,125 @@
+/*============================================================================
+  CMake - Cross Platform Makefile Generator
+  Copyright 2000-2009 Kitware, Inc., Insight Software Consortium
+
+  Distributed under the OSI-approved BSD License (the "License");
+  see accompanying file Copyright.txt for details.
+
+  This software is distributed WITHOUT ANY WARRANTY; without even the
+  implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
+  See the License for more information.
+============================================================================*/
+#include <cm_utf8.h>
+
+#include <string.h>
+#include <stdio.h>
+
+typedef char test_utf8_char[5];
+
+static void test_utf8_char_print(test_utf8_char const c)
+{
+  unsigned char const* d = reinterpret_cast<unsigned char const*>(c);
+  printf("[0x%02X,0x%02X,0x%02X,0x%02X]",
+         (int)d[0], (int)d[1], (int)d[2], (int)d[3]);
+}
+
+struct test_utf8_entry
+{
+  int n;
+  test_utf8_char str;
+  unsigned int chr;
+};
+
+static test_utf8_entry const good_entry[] = {
+  {1, "\x20\x00\x00\x00", 0x0020},  /* Space.  */
+  {2, "\xC2\xA9\x00\x00", 0x00A9},  /* Copyright.  */
+  {3, "\xE2\x80\x98\x00", 0x2018},  /* Open-single-quote.  */
+  {3, "\xE2\x80\x99\x00", 0x2019},  /* Close-single-quote.  */
+  {4, "\xF0\xA3\x8E\xB4", 0x233B4}, /* Example from RFC 3629.  */
+  {0, {0,0,0,0,0}, 0}
+};
+
+static test_utf8_char const bad_chars[] = {
+  "\x80\x00\x00\x00",
+  "\xC0\x00\x00\x00",
+  "\xE0\x00\x00\x00",
+  "\xE0\x80\x80\x00",
+  "\xF0\x80\x80\x80",
+  {0,0,0,0,0}
+};
+
+static void report_good(bool passed, test_utf8_char const c)
+{
+  printf("%s: decoding good ", passed?"pass":"FAIL");
+  test_utf8_char_print(c);
+  printf(" (%s) ", c);
+}
+
+static void report_bad(bool passed, test_utf8_char const c)
+{
+  printf("%s: decoding bad  ", passed?"pass":"FAIL");
+  test_utf8_char_print(c);
+  printf(" ");
+}
+
+static bool decode_good(test_utf8_entry const entry)
+{
+  unsigned int uc;
+  if(const char* e = cm_utf8_decode_character(entry.str, entry.str+4, &uc))
+    {
+    int used = static_cast<int>(e-entry.str);
+    if(uc != entry.chr)
+      {
+      report_good(false, entry.str);
+      printf("expected 0x%04X, got 0x%04X\n", entry.chr, uc);
+      return false;
+      }
+    if(used != entry.n)
+      {
+      report_good(false, entry.str);
+      printf("had %d bytes, used %d\n", entry.n, used);
+      return false;
+      }
+    report_good(true, entry.str);
+    printf("got 0x%04X\n", uc);
+    return true;
+    }
+  report_good(false, entry.str);
+  printf("failed\n");
+  return false;
+}
+
+static bool decode_bad(test_utf8_char const s)
+{
+  unsigned int uc = 0xFFFFu;
+  const char* e = cm_utf8_decode_character(s, s+4, &uc);
+  if(e)
+    {
+    report_bad(false, s);
+    printf("expected failure, got 0x%04X\n", uc);
+    return false;
+    }
+  report_bad(true, s);
+  printf("failed as expected\n");
+  return true;
+}
+
+int testUTF8(int, char*[])
+{
+  int result = 0;
+  for(test_utf8_entry const* e = good_entry; e->n; ++e)
+    {
+    if(!decode_good(*e))
+      {
+      result = 1;
+      }
+    }
+  for(test_utf8_char const* c = bad_chars; (*c)[0]; ++c)
+    {
+    if(!decode_bad(*c))
+      {
+      result = 1;
+      }
+    }
+  return result;
+}