CTest: Do not munge UTF-8 output in XML files

CTest filters the output from tools and tests to ensure that the XML
build/test result documents it generates have valid characters.
Previously we just converted all non-ASCII bytes into XML-escaped
Unicode characters of the corresponding index.  This does not preserve
tool output encoded in UTF-8.

We now assume UTF-8 output from tools and implement decoding as
specified in RFC 3629.  Valid characters are preserved, possibly with
XML escaping.  Invalid byte sequences and characters are converted to
human-readable hex values with distinguishing tags.  See issue #10003.

1 files changed, 84 insertions, 0 deletions

diff --git a/Source/cm_utf8.c b/Source/cm_utf8.c
new file mode 100644
index 0000000000..3d4ca16eed
--- /dev/null
+++ b/Source/cm_utf8.c
@@ -0,0 +1,84 @@
+/*============================================================================
+  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"
+
+/*
+  RFC 3629
+  07-bit: 0xxxxxxx
+  11-bit: 110xxxxx 10xxxxxx
+  16-bit: 1110xxxx 10xxxxxx 10xxxxxx
+  21-bit: 11110xxx 10xxxxxx 10xxxxxx 10xxxxxx
+
+  Pre-RFC Compatibility
+  26-bit: 111110xx 10xxxxxx 10xxxxxx 10xxxxxx 10xxxxxx
+  31-bit: 1111110x 10xxxxxx 10xxxxxx 10xxxxxx 10xxxxxx 10xxxxxx
+*/
+
+/* Number of leading ones before a zero in the byte.  */
+static unsigned char const cm_utf8_ones[256] = {
+  0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,
+  0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,
+  0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,
+  0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,
+  1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,
+  1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,
+  2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,
+  3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,4,4,4,4,4,4,4,4,5,5,5,5,6,6,7,8
+};
+
+/* Mask away control bits from bytes with n leading ones.  */
+static unsigned char const cm_utf8_mask[7] = {
+  0xEF, 0x3F, 0x1F, 0x0F, 0x07, 0x03, 0x01
+};
+
+/* Minimum allowed value when first byte has n leading ones.  */
+static unsigned int const cm_utf8_min[7] = {
+  0, 0, 1u<<7, 1u<<11, 1u<<16, 1u<<21, 1u<<26 /*, 1u<<31 */
+};
+
+/*--------------------------------------------------------------------------*/
+const char* cm_utf8_decode_character(const char* first, const char* last,
+                                     unsigned int* pc)
+{
+  /* Count leading ones in the first byte.  */
+  unsigned char c = *first++;
+  unsigned char const ones = cm_utf8_ones[c];
+  switch(ones)
+    {
+    case 0: *pc = c; return first;    /* One-byte character.  */
+    case 1: case 7: case 8: return 0; /* Invalid leading byte.  */
+    default: break;
+    }
+
+  /* Extract bits from this multi-byte character.  */
+  {
+  unsigned int uc = c & cm_utf8_mask[ones];
+  unsigned char left;
+  for(left = ones-1; left && first != last; --left)
+    {
+    c = *first++;
+    if(cm_utf8_ones[c] != 1)
+      {
+      return 0;
+      }
+    uc = (uc << 6) | (c & cm_utf8_mask[1]);
+    }
+
+  if(left > 0 || uc < cm_utf8_min[ones])
+    {
+    return 0;
+    }
+
+  *pc = uc;
+  return first;
+  }
+}