PR10543: do module cache cleaning before copying new file into the cache

... otherwise the new stuff can get cleaned before use.

* cache.cxx (add_to_cache): Do clean_cache() first, not last.

2 files changed, 5 insertions, 3 deletions

diff --git a/cache.cxx b/cache.cxx
index ee6d0bf6..b1c7908f 100644
--- a/cache.cxx
+++ b/cache.cxx
@@ -48,6 +48,10 @@ static void clean_cache(systemtap_session& s);
 void
 add_to_cache(systemtap_session& s)
 {
+  // PR10543: clean the cache *before* we try putting something new into it.
+  // We don't want to risk having the brand new contents being erased again.
+  clean_cache(s);
+
   string stapconf_src_path = s.tmpdir + "/" + s.stapconf_name;
   if (s.verbose > 1)
     clog << "Copying " << stapconf_src_path << " to " << s.stapconf_path << endl;
@@ -117,8 +121,6 @@ add_to_cache(systemtap_session& s)
       //
       // s.use_cache = false;
     }
-
-  clean_cache(s);
 }
 
 
diff --git a/main.cxx b/main.cxx
index bc0d7389..15447efc 100644
--- a/main.cxx
+++ b/main.cxx
@@ -1229,7 +1229,7 @@ main (int argc, char * const argv [])
          << endl;
   else
     {
-      // Update cache. Cache cleaning is kicked off at the end of this function.
+      // Update cache. Cache cleaning is kicked off at the beginning of this function.
       if (s.use_cache)
         add_to_cache(s);