message: Highlight non-breaking space within text
diff: @@ -45,6 +45,7 @@ public:
  const int length = int(s.length());
  + // Leading whitespace:
  for (auto i = s.begin(); i != s.end(); ++i)
  {
  if (!u_isblank(*i))
  @@ -56,6 +57,7 @@ public:
  }
  }
  + // Trailing whitespace:
  for (auto i = s.rbegin(); i != s.rend(); ++i)
  {
  if (!u_isblank(*i))
  @@ -71,7 +73,15 @@ public:
  for (auto i = s.begin(); i != s.end(); ++i)
  {
  - if (u_isblank(*i))
  + // Some special whitespace characters should always be highlighted:
  + if (*i == 0x00A0 /*non-breakable space*/)
  + {
  + int pos = int(i - s.begin());
  + highlight(pos, pos + 1, LeadingWhitespace);
  + }
  +
  + // Duplicate whitespace (2+ spaces etc.):
  + else if (u_isblank(*i))
  {
  if (blank_block_pos == -1)
  blank_block_pos = int(i - s.begin());
  @@ -84,6 +94,7 @@ public:
  blank_block_pos = -1;
  }
  + // Escape sequences:
  if (*i == '\\')
  {
  int pos = int(i - s.begin());
  