follow Lmod rules for path updates

INSTALL.rst

@@ -1723,6 +1723,9 @@ installation.
 |                                   |                                              | :envvar:`MODULES_PAGER`,                     |              |           |
 |                                   |                                              | :option:`--paginate`, :option:`--no-pager`   |              |           |
 +-----------------------------------+----------------------------------------------+----------------------------------------------+--------------+-----------+
+| :mconfig:`path_entry_reorder`     | ``0``                                        | :instopt:`--enable-path-entry-reorder`,      |              |           |
+|                                   |                                              | :envvar:`MODULES_PATH_ENTRY_REORDER`         |              |           |
++-----------------------------------+----------------------------------------------+----------------------------------------------+--------------+-----------+
 | :mconfig:`protected_envvars`      | *Unset by default*                           | :envvar:`MODULES_PROTECTED_ENVVARS`          |              |           |
 +-----------------------------------+----------------------------------------------+----------------------------------------------+--------------+-----------+
 | :mconfig:`quarantine_support`     | ``0``                                        | :instopt:`--enable-quarantine-support`,      | X            |           |

Makefile

@@ -395,6 +395,12 @@ else
   setwa277 := 0
 endif
 
+ifeq ($(pathentryreorder),y)
+  setpathentryreorder := 1
+else
+  setpathentryreorder := 0
+endif
+
 ifneq ($(tcllinteropts),)
   tcllintercmd := $(tcllinter) $(tcllinteropts)
 else
@@ -443,6 +449,7 @@ sed -e 's|@prefix@|$(prefix)|g' \
 	-e 's|@sourcecache@|$(setsourcecache)|g' \
 	-e 's|@searchmatch@|$(searchmatch)|g' \
 	-e 's|@wa277@|$(setwa277)|g' \
+	-e 's|@pathentryreorder@|$(setpathentryreorder)|g' \
 	-e 's|@icase@|$(icase)|g' \
 	-e 's|@nearlyforbiddendays@|$(nearlyforbiddendays)|g' \
 	-e 's|@tagabbrev@|$(tagabbrev)|g' \

Makefile.inc.in

@@ -158,6 +158,9 @@ variantshortcut := @variantshortcut@
 # editor
 editor := @editor@
 
+# Lmod path order
+pathentryreorder := @pathentryreorder@
+
 # shell completion location
 bashcompletiondir := @bashcompletiondir@
 fishcompletiondir := @fishcompletiondir@

configure

@@ -34,7 +34,7 @@ multilibsupport libdir64 libdir32 versioning silentshdbgsupport \
 setshellstartup quarantinesupport autohandling availindepth implicitdefault \
 extendeddefault moduleshome initconfin pager pageropts verbosity color \
 darkbgcolors lightbgcolors termbg lockedconfigs icase unloadmatchorder \
-searchmatch modulepath loadedmodules quarantinevars wa277 advversspec ml \
+searchmatch modulepath loadedmodules quarantinevars wa277 pathentryreorder advversspec ml \
 windowssupport nearlyforbiddendays implicitrequirement tagabbrev \
 tagcolorname mcookieversioncheck availoutput availterseoutput listoutput \
 listterseoutput editor variantshortcut bashcompletiondir fishcompletiondir \
@@ -79,6 +79,7 @@ extendeddefault=y
 advversspec=y
 ml=y
 wa277=n
+pathentryreorder=n
 loadedmodules=
 quarantinevars=
 binsearchpath=/usr/bin:/bin:/usr/local/bin
@@ -803,6 +804,9 @@ for arg in "$@"; do
    --enable-mcookie-version-check*|--disable-mcookie-version-check)
       # shellcheck disable=SC2034
       mcookieversioncheck=$(get_feature_value "$arg") ;;
+   --enable-path-entry-reorder*|--disable-path-entry-reorder)
+      # shellcheck disable=SC2034
+      pathentryreorder=$(get_feature_value "$arg") ;;
    --with-bin-search-path=*|--without-bin-search-path)
       binsearchpath=$(get_package_value "$arg") ;;
    --with-moduleshome=*|--without-moduleshome)

doc/source/changes.rst

@@ -1279,6 +1279,8 @@ The following Modules configuration option has been introduced on Modules 5.
 | 5.6        | :mconfig:`spider_output`, :mconfig:`spider_terse_output`,       |
 |            | :mconfig:`spider_indepth`, :mconfig:`require_via`               |
 +------------+-----------------------------------------------------------------+
+| 5.7        | :mconfig:`path_entry_reorder`                                   |
++------------+-----------------------------------------------------------------+
 
 :mconfig:`auto_handling`
 

doc/source/module.rst

@@ -1370,6 +1370,23 @@ Module Sub-Commands
   sub-command when changing this configuration option from its default value.
   See :envvar:`MODULES_PAGER` description for details.
 
+ .. mconfig:: path_entry_reorder
+
+  Change order of entry in a path-like environment variable, when 
+  :mfcmd:`prepend-path`, :mfcmd:`append-path` or :subcmd:`use` target 
+  a path entry that is already defined in the environment variable.
+
+  Default value is ``0``. It can be changed at installation time with the
+  :instopt:`--with-path-entry-reorder` option. The
+  :envvar:`MODULES_PATH_ENTRY_REORDER` environment variable is defined by
+  :subcmd:`config` sub-command when changing this configuration option from
+  its default value. See :envvar:`MODULES_PATH_ENTRY_REORDER` description
+  for details.
+
+  .. only:: html
+
+     .. versionadded:: 5.x
+
  .. mconfig:: protected_envvars
 
   Prevents any modification of listed environment variables (colon `:`
@@ -5274,6 +5291,35 @@ ENVIRONMENT
     .. versionchanged:: 5.5
        No pager when :file:`modulecmd.tcl` is run for scripting languages
 
+.. envvar:: MODULES_PATH_ENTRY_REORDER
+
+ This environment variable changes the behavior of :mfcmd:`prepend-path`, :mfcmd:`append-path` and :subcmd:`use`.
+
+ If set to ``1``, and one of these commands targets a path entry that already exists in the environment variable, the entry is moved to the beginning or end (depending on the command), unless duplicates are allowed. This is the default behavior in Lmod.
+ If set to ``0``, the environment variable is not modified when the entry already exists.
+
+ Example:
+
+  .. parsed-literal::
+
+   :ps:`$` module config path_entry_reorder 0
+   :ps:`$` module append-path PATHVAR /foo
+   :ps:`$` module append-path PATHVAR /bar
+   :ps:`$` module append-path PATHVAR /foo
+   :ps:`$` echo $PATHVAR
+   /foo:/bar
+   :ps:`$` module config path_entry_reorder 1
+   :ps:`$` module append-path PATHVAR /foo
+   :ps:`$` echo $PATHVAR
+   /bar:/foo
+   :ps:`$` module append-path --duplicates PATHVAR /bar
+   :ps:`$` echo $PATHVAR
+   /bar:/foo:/bar
+
+ .. only:: html
+
+    .. versionadded:: 5.x
+
 .. envvar:: MODULES_PROTECTED_ENVVARS
 
  A colon separated list of environment variable names that should not be

init/Makefile

@@ -136,7 +136,7 @@ comp_lint_opts := -a -i --all --icase
 comp_modtosh_opts := --auto --no-auto --force -f --icase -i
 comp_path_opts := -d --delim --duplicates
 comp_rm_path_opts := -d --delim --index
-comp_config_opts := --dump-state --reset abort_on_error advanced_version_spec auto_handling avail_indepth avail_output avail_terse_output cache_buffer_bytes cache_expiry_secs collection_pin_version collection_pin_tag collection_target color colors conflict_unload contact editor extended_default extra_siteconfig hide_auto_loaded home icase ignore_cache ignore_user_rc implicit_default implicit_requirement list_output list_terse_output locked_configs logged_events logger mcookie_check mcookie_version_check ml nearly_forbidden_days pager protected_envvars quarantine_support rcfile redirect_output require_via reset_target_state run_quarantine search_match set_shell_startup shells_with_ksh_fpath silent_shell_debug source_cache spider_indepth spider_output spider_terse_output sticky_purge tag_abbrev tag_color_name tcl_linter term_background term_width unique_name_loaded unload_match_order variant_shortcut verbosity wa_277
+comp_config_opts := --dump-state --reset abort_on_error advanced_version_spec auto_handling avail_indepth avail_output avail_terse_output cache_buffer_bytes cache_expiry_secs collection_pin_version collection_pin_tag collection_target color colors conflict_unload contact editor extended_default extra_siteconfig hide_auto_loaded home icase ignore_cache ignore_user_rc implicit_default implicit_requirement list_output list_terse_output locked_configs logged_events logger mcookie_check mcookie_version_check ml nearly_forbidden_days pager path_entry_reorder protected_envvars quarantine_support rcfile redirect_output require_via reset_target_state run_quarantine search_match set_shell_startup shells_with_ksh_fpath silent_shell_debug source_cache spider_indepth spider_output spider_terse_output sticky_purge tag_abbrev tag_color_name tcl_linter term_background term_width unique_name_loaded unload_match_order variant_shortcut verbosity wa_277
 
 define translate-in-script
 $(ECHO_GEN)
@@ -167,6 +167,7 @@ sed -e 's|@prefix@|$(prefix)|g' \
 	-e 's|@comp_path_opts@|$(comp_path_opts)|g' \
 	-e 's|@comp_rm_path_opts@|$(comp_rm_path_opts)|g' \
 	-e 's|@comp_config_opts@|$(comp_config_opts)|g' \
+	-e 's|@comp_path_entry_reorder@|$(comp_path_entry_reorder)|g' \
 	-e '$(setzshfpathre)' \
 	-e $$'s|@modulerc@|$(modulerc)|g' \
 	-e 's|@modulepath@|$(modulepath)|g' \

init/fish_completion

@@ -87,7 +87,7 @@ complete -c module -n '__fish_module_use_stashlist' -f -a "(module stashlist --c
    /Stash collection list\$/d; \
    /:\$/d; \
    /:ERROR:/d;')"
-complete -c module -n '__fish_module_use_config' -f -a "--dump-state --reset abort_on_error advanced_version_spec auto_handling avail_indepth avail_output avail_terse_output cache_buffer_bytes cache_expiry_secs collection_pin_version collection_pin_tag collection_target color colors conflict_unload contact editor extended_default extra_siteconfig hide_auto_loaded home icase ignore_cache ignore_user_rc implicit_default implicit_requirement list_output list_terse_output locked_configs logged_events logger mcookie_check mcookie_version_check ml nearly_forbidden_days pager protected_envvars quarantine_support rcfile redirect_output require_via reset_target_state run_quarantine search_match set_shell_startup shells_with_ksh_fpath silent_shell_debug source_cache spider_indepth spider_output spider_terse_output sticky_purge tag_abbrev tag_color_name tcl_linter term_background term_width unique_name_loaded unload_match_order variant_shortcut verbosity wa_277"
+complete -c module -n '__fish_module_use_config' -f -a "--dump-state --reset abort_on_error advanced_version_spec auto_handling avail_indepth avail_output avail_terse_output cache_buffer_bytes cache_expiry_secs collection_pin_version collection_pin_tag collection_target color colors conflict_unload contact editor extended_default extra_siteconfig hide_auto_loaded home icase ignore_cache ignore_user_rc implicit_default implicit_requirement list_output list_terse_output locked_configs logged_events logger mcookie_check mcookie_version_check ml nearly_forbidden_days pager path_entry_reorder protected_envvars quarantine_support rcfile redirect_output require_via reset_target_state run_quarantine search_match set_shell_startup shells_with_ksh_fpath silent_shell_debug source_cache spider_indepth spider_output spider_terse_output sticky_purge tag_abbrev tag_color_name tcl_linter term_background term_width unique_name_loaded unload_match_order variant_shortcut verbosity wa_277"
 
 complete -f -n '__fish_module_no_subcommand' -c module -a 'help' --description 'Print this or modulefile(s) help info'
 complete -f -n '__fish_module_no_subcommand' -c module -a 'avail' --description 'List all or matching available modules'

init/zsh-functions/_module.in

@@ -378,7 +378,7 @@ _module() {
                _arguments \
                   '--dump-state[Report each state value of current Modules execution]' \
                   '--reset[Unset environment variable relative to configuration key]' \
-                  '1:configuration key:(abort_on_error advanced_version_spec auto_handling avail_indepth avail_output avail_terse_output cache_buffer_bytes cache_expiry_secs collection_pin_version collection_pin_tag collection_target color colors conflict_unload contact editor extended_default extra_siteconfig hide_auto_loaded home icase ignore_cache ignore_user_rc implicit_default implicit_requirement list_output list_terse_output locked_configs logged_events logger mcookie_check mcookie_version_check ml nearly_forbidden_days pager protected_envvars quarantine_support rcfile redirect_output require_via reset_target_state run_quarantine search_match set_shell_startup shells_with_ksh_fpath silent_shell_debug source_cache spider_indepth spider_output spider_terse_output sticky_purge tag_abbrev tag_color_name tcl_linter term_background term_width unique_name_loaded unload_match_order variant_shortcut verbosity wa_277)' \
+                  '1:configuration key:(abort_on_error advanced_version_spec auto_handling avail_indepth avail_output avail_terse_output cache_buffer_bytes cache_expiry_secs collection_pin_version collection_pin_tag collection_target color colors conflict_unload contact editor extended_default extra_siteconfig hide_auto_loaded home icase ignore_cache ignore_user_rc implicit_default implicit_requirement list_output list_terse_output locked_configs logged_events logger mcookie_check mcookie_version_check ml nearly_forbidden_days pager path_entry_reorder protected_envvars quarantine_support rcfile redirect_output require_via reset_target_state run_quarantine search_match set_shell_startup shells_with_ksh_fpath silent_shell_debug source_cache spider_indepth spider_output spider_terse_output sticky_purge tag_abbrev tag_color_name tcl_linter term_background term_width unique_name_loaded unload_match_order variant_shortcut verbosity wa_277)' \
                   && ret=0
                ;;
             (edit)

site.exp.in

@@ -117,6 +117,8 @@ set install_variantshortcut "@variantshortcut@"
 
 set install_editor "@editor@"
 
+set install_pathentryreorder "@pathentryreorder@"
+
 set install_bashcompletiondir "@bashcompletiondir@"
 set install_fishcompletiondir "@fishcompletiondir@"
 set install_zshcompletiondir "@zshcompletiondir@"

tcl/envmngt.tcl.in

@@ -1808,27 +1808,43 @@ proc add-path {cmd mode dflbhv args} {
    set val [get-env $var]
 
    foreach dir $path_list {
-      if {![info exists countarr($dir)] || $allow_dup} {
+      # remove $dir from path only if path_entry_reorder is true and
+      # $dir is already in path and duplicates are NOT allowed.
+      if {[getConf path_entry_reorder] && [info exists countarr($dir)]\
+         && ! $allow_dup} {
+         set mpath_list [split $val $separator]
+         set mpath_list [lsearch -inline -all -not -exact $mpath_list $dir]
+         set val [join $mpath_list $separator]
+      }
+      # add $dir to beginning or end only if path_entry_reorder is true or
+      # $dir is NOT in path or duplicates are allowed.
+      # Please note: if path_entry_reorder is true and duplicates are not
+      # allowed, $dir is not in path ($val) - either it was not in or it
+      # had been removed. Hence we have to add it.
+      if {[getConf path_entry_reorder] || ![info exists countarr($dir)]\
+         || $allow_dup} {
          # ignore env var set empty if no empty entry found in reference
          # counter array (sometimes var is cleared by setting it empty not
          # unsetting it)
          if {$val ne {} || [info exists countarr()]} {
             set sep [expr {$val eq $separator ? {} : $separator}]
             set val [expr {$bhv eq {prepend} ? "$dir$sep$val" :\
-               "$val$sep$dir"}]
+                              "$val$sep$dir"}]
          } else {
             set val $dir
          }
       }
-      if {[info exists countarr($dir)]} {
-         # do not increase counter if bare separator string is added or if
-         # reference count is ignored (--ignore-refcount set) unless if
-         # duplicate mode is enabled (--duplicates set)
-         if {!$val_set_is_delim && (!$ign_refcount || $allow_dup)} {
-            incr countarr($dir)
-         }
-      } else {
+      #### ref-counting
+      # if $dir is NOT in path
+      #    set ref-count 1
+      # else
+      #    do NOT increase counter if bare separator string is added or if
+      #    reference count is ignored (--ignore-refcount set) unless if
+      #    duplicate mode is enabled (--duplicates set)
+      if {![info exists countarr($dir)]} {
          set countarr($dir) 1
+      } elseif {!$val_set_is_delim && (!$ign_refcount || $allow_dup)} {
+         incr countarr($dir)
       }
    }
 
@@ -2046,7 +2062,10 @@ proc getModulesEnvVarGlobList {{loaded_ctx 0}} {
    return $envvar_glob_list
 }
 
-# ;;; Local Variables: ***
-# ;;; mode:tcl ***
-# ;;; End: ***
+# ;;; Local Variables:
+# ;;; Mode: tcl-mode
+# ;;; tcl-indent-level: 3
+# ;;; tcl-continued-indent-level: 3
+# ;;; indent-tabs-mode: nil
+# ;;; End:
 # vim:set tabstop=3 shiftwidth=3 expandtab autoindent:

tcl/init.tcl.in

@@ -122,6 +122,7 @@ array set g_config_defs [list\
    nearly_forbidden_days {MODULES_NEARLY_FORBIDDEN_DAYS @nearlyforbiddendays@\
       0 i {0 365} {} {} intbe}\
    pager {MODULES_PAGER {@pagercmd@} 0 s}\
+   path_entry_reorder {MODULES_PATH_ENTRY_REORDER @pathentryreorder@ 0 b {0 1}}\
    protected_envvars {MODULES_PROTECTED_ENVVARS <undef> 0 l}\
    rcfile {MODULERCFILE <undef> 0 l}\
    redirect_output {MODULES_REDIRECT_OUTPUT 1 0 b {0 1}}\

tcl/subcmd.tcl.in

@@ -3152,7 +3152,10 @@ proc cmdModuleSpider {show_oneperline show_mtime show_filter search_filter\
       $search_match $modpath_list {*}$args
 }
 
-# ;;; Local Variables: ***
-# ;;; mode:tcl ***
-# ;;; End: ***
+# ;;; Local Variables:
+# ;;; Mode: tcl-mode
+# ;;; tcl-indent-level: 3
+# ;;; tcl-continued-indent-level: 3
+# ;;; indent-tabs-mode: nil
+# ;;; End:
 # vim:set tabstop=3 shiftwidth=3 expandtab autoindent:

testsuite/install.00-init/010-environ.exp

@@ -194,4 +194,7 @@ catch {unset env(MODULERCFILE)}
 # setup basic locale for tests
 set env(LANG) "C"
 
+# ensure that tests doesn't run with Lmod path order
+unsetenv_var MODULES_PATH_ENTRY_REORDER
+
 # vim:set tabstop=3 shiftwidth=3 expandtab autoindent:

testsuite/modules.00-init/010-environ.exp

@@ -188,6 +188,9 @@ catch {unset env(MODULES_COLLECTION_TARGET)}
 catch {unset env(MODULE_VERSION)}
 catch {unset env(MODULE_VERSION_STACK)}
 
+# ensure that tests doesn't run with Lmod path order
+unsetenv_var MODULES_PATH_ENTRY_REORDER
+
 set env(MODULERCFILE) "$env(TESTSUITEDIR)/etc/empty"
 set ORIG_MODULERCFILE $env(MODULERCFILE)
 catch {unset env(MODULESHOME)}

testsuite/modules.70-maint/220-config.exp

@@ -93,6 +93,7 @@ array set configdfl [list\
     ml                        [expr {$install_ml eq {y}}]\
     nearly_forbidden_days     $install_nearlyforbiddendays\
     pager                     "$install_pagercmd"\
+    path_entry_reorder        [expr {$install_pathentryreorder eq {y}}]\
     protected_envvars         <undef>\
     quarantine_support        [expr {$install_quarantinesupport eq {y}}]\
     rcfile                    <undef>\
@@ -158,6 +159,7 @@ array set configvar [list\
     ml                        MODULES_ML\
     nearly_forbidden_days     MODULES_NEARLY_FORBIDDEN_DAYS\
     pager                     MODULES_PAGER\
+    path_entry_reorder        MODULES_PATH_ENTRY_REORDER\
     protected_envvars         MODULES_PROTECTED_ENVVARS\
     quarantine_support        MODULES_QUARANTINE_SUPPORT\
     rcfile                    MODULERCFILE\
@@ -213,6 +215,7 @@ array set configvalid [list\
     mcookie_version_check     {0 1}\
     ml                        {0 1}\
     nearly_forbidden_days     {0 365}\
+    path_entry_reorder        {0 1}\
     quarantine_support        {0 1}\
     redirect_output           {0 1}\
     require_via               {0 1}\