The search for "temporary fix" picks up a lot of snippets like the following, which is code that manipulates temporary files (e.g., files in /tmp that are removed after a process exits), not "temporary fixes":

  #ifndef FIX_TEMPORARY_FILE_HH_
  #define FIX_TEMPORARY_FILE_HH_

  namespace fix {
  struct temporary_file {
      explicit temporary_file(boost::filesystem::path p);

This one is apparently code for a tool that reviews code. It doesn't look like temporary code at all:

  package de.setsoftware.reviewtool.model;

  public enum RemarkType {
	MUST_FIX,
	CAN_FIX,
	ALREADY_FIXED,
	POSITIVE,
	TEMPORARY
  }

Also, most temporary fixes probably aren't explicitly commented as such. So this search is picking up lots of things that are not temporary fixes while probably missing the vast majority of the real ones. Thus it looks like the methodology for this survey is quite flawed.

They usually end to be the most permanent ones ...