Merge branch '3.4-maint'

* 3.4-maint:
  Hash preprocessed headers located in “.gch directories” correctly

diff --cc doc/NEWS.txt
index fa7e69f84d7fd5dcc5e38105925e73ac2444e576,e306fb34061448919363cb1b86295ebb6a1af32d..c765cc1b62b2e0ec1c8a51e4625181025d3a984d
--- 1/doc/NEWS.txt
--- 2/doc/NEWS.txt
+++ b/doc/NEWS.txt
@@@ -1,17 -1,18 +1,29 @@@
  ccache news
  ===========
  
 +ccache 3.5
 +----------
 +Release date: unknown
 +
 +New features and enhancements
 +~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
 +
 +- Renamed `CCACHE_CC` to `CCACHE_COMPILER` (keeping the former as a deprecated
 +  alias).
 +
 +
+ ccache 3.4.2
+ ------------
+ Release date: unknown
+ 
+ Bug fixes
+ ~~~~~~~~~
+ 
+ - Correctly hash preprocessed headers located in a ``.gch directory''.
+   Previously, ccache would not pick up changes to such precompiled headers,
+   risking false positive cache hits.
+ 
+ 
  ccache 3.4.1
  ------------
  Release date: 2018-02-11