Change approach with version req in cache file magic cookie

Version in magic cookie of cache files was previously set to the current
version of Modules. As a result, only the same Modules version would be
able to use cache file generated.

This is changed to enable use of cache files by several Modules release.
Only a cache format change would imply a magic cookie version upgrade.

So as of now, the version required is set to 5.3. This will change if
the cache format evolves (with new cache file Tcl commands or a change
in the arguments of the existing commands).

Version requirement is set to 5.3 as commands in cache files as not been
changed since the introduction of the cache feature in Modules 5.3
release.

Signed-off-by: Xavier Delaruelle <[email protected]>

Author: xdelaruelle

tcl/cache.tcl.in

@@ -186,8 +186,8 @@ proc formatModuleCacheContent {modpath} {
 
    # prepend header if some content has been generated
    if {[string length $content]} {
-      regexp {^\d+\.\d+} [getState modules_release] majmin
-      set content "#%Module$majmin$content"
+      set cache_header "#%Module[getState cache_mcookie_version]"
+      set content $cache_header$content
    }
 
    return $content

tcl/init.tcl.in

@@ -22,9 +22,10 @@
 
 # Runtime state properties (default value, proc to call to initialize state
 # value?)
-##nagelfar ignore +37 Found constant
+##nagelfar ignore +38 Found constant
 array set g_state_defs [list\
    autoinit {0}\
+   cache_mcookie_version {5.3}\
    clock_seconds {<undef> initStateClockSeconds}\
    domainname {<undef> {runCommand domainname}}\
    error_count {0}\