Issue 1115 - Some yahoo page not correctly shown on IE8 when ABP enabled

src/shared/Utils.cpp

 /*
  * This file is part of Adblock Plus <https://adblockplus.org/>,
  * Copyright (C) 2006-2015 Eyeo GmbH
  *
  * Adblock Plus is free software: you can redistribute it and/or modify
  * it under the terms of the GNU General Public License version 3 as
  * published by the Free Software Foundation.
  *
  * Adblock Plus is distributed in the hope that it will be useful,
  * but WITHOUT ANY WARRANTY; without even the implied warranty of
@@ skipping 129 matching lines @@
 }
 
 void ReplaceString(std::wstring& input, const std::wstring placeholder, const std::wstring replacement)
 {
   size_t replaceStart = input.find(placeholder);
   if (replaceStart != std::string::npos)
   {
     input.replace(replaceStart, placeholder.length(), replacement);
   }
 }
+
+std::wstring GetSchemeAndHierarchicalPart(const std::wstring& url)
+{
+  auto schemeAndHierarchicalPartEndsAt = url.find(L'?');
+  if (schemeAndHierarchicalPartEndsAt == std::wstring::npos)
+  {
+    schemeAndHierarchicalPartEndsAt = url.find(L'#');

[Oleksandr, 2015/02/13 03:32:16]

So what if there's neither '?' nor '#' in the url?
Even more, why not just use CreateUri
(https://msdn.microsoft.com/en-us/library/ie/ms775098(v=vs.85).aspx) and then
just IUri::GetQuery? Or maybe WinHttpCrackUrl or InternetCrackUrl. For this and
GetQueryString below.
https://msdn.microsoft.com/en-us/library/windows/desktop/aa384092%28v=vs.85%2...
or
https://msdn.microsoft.com/en-us/library/windows/desktop/aa384376(v=vs.85).aspx

[sergei, 2015/02/13 15:21:56]

It means there is neither query nor fragment and we will return the original
URL. Actually, there is the test for that case.
I thought that it's an unnecessary overhead, especially I'm afraid that to parse
the URL they can instantiate a protocol handler (BTW, our implementation of
protocol handler) to use IInternetProtocolInfo::ParseUrl. At least I've seen
such behaviour but I don't remember whether it was for one of the mentioned
function or not.
CreateUri looks fine for me, should I investigate it and change?

[Oleksandr, 2015/02/16 06:59:28]

We are using WinHTTPCrackUrl in libadblockplus in DedfaultWebRequestWinInet.cpp,
FYI. I don't think that instantiates our APP. But at this stage, I guess there
is little point to look into CreateUrl and others since we already have a good
enough solution with tests.

+  }
+  return url.substr(0, schemeAndHierarchicalPartEndsAt);
+}
+
+std::wstring GetQueryString(const std::wstring& url)
+{
+  auto questionSignPos = url.find(L'?');
+  if (questionSignPos == std::wstring::npos)
+  {
+    return L"";
+  }
+  auto queryStringBeginsAt = questionSignPos + 1;
+  auto endQueryStringPos = url.find(L'#', queryStringBeginsAt);
+  if (endQueryStringPos == std::wstring::npos)
+  {
+    endQueryStringPos = url.length();
+  }
+  return url.substr(queryStringBeginsAt, endQueryStringPos - queryStringBeginsAt);
+}

[Eric, 2015/02/12 17:24:41]

This version much clearer and easier to verify correctness, including better
local variable names.

+
+void ForEachToken(const std::wstring& value, wchar_t delimiter,
+                 const std::function<bool(std::wstring::const_iterator begin, std::wstring::const_iterator end)>& tokenHandler)
+{
+  if (value.empty())
+  {
+    return;
+  }
+  std::wstring::size_type delimiterPos = value.find(delimiter);
+  std::wstring::size_type prevDelimiterPos = 0;
+  while(delimiterPos != std::wstring::npos)
+  {
+    if (!tokenHandler(value.begin() + prevDelimiterPos, value.begin() + delimiterPos))
+    {
+      return;
+    }
+    prevDelimiterPos = delimiterPos;
+    ++prevDelimiterPos; // skip the delimiter
+    delimiterPos = value.find(delimiter, prevDelimiterPos);
+  }
+  tokenHandler(value.begin() + prevDelimiterPos, value.end());
+}
+
+void ForEachQueryStringParameter(const std::wstring& queryString,
+                                 const std::function<bool(const std::wstring& name, const std::wstring& value)>& parameterHandler)
+{
+  if (queryString.empty())
+  {
+    return;
+  }
+  ForEachToken(queryString, L'&',
+    [&parameterHandler](std::wstring::const_iterator begin,
+                        std::wstring::const_iterator end)->bool
+    {
+      auto assignSignIt = std::find(begin, end, L'=');
+      auto valueBeginsAt = assignSignIt != end ? assignSignIt + 1 : assignSignIt;
+      return parameterHandler(std::wstring(begin, assignSignIt), std::wstring(valueBeginsAt, end));
+    });
+}