zshrc: fix zcleanup

previously zcleanup had acquired some regressions:
- _sev_tmp was changed to be a link, which caused `find` to fail without -L
- pid selection was broken
- logic was not unified, so some code paths were making incorrect assumptions
- if tmp failed to be removed, superfluous errors could be shown

zcleanup now removes all session dirs with this criteria:
- pid is ourselves (stale session or was forced to cleanup)
- pid is dead
- pid is alive and not a zsh

the dir is also now reused in tmp generation in case it exists, instead of
showing an error; this really shouldn't happen but I think it's saner

diff --git a/etc/zsh/.zshenv b/etc/zsh/.zshenv
index 37daf7fc58bceecc1c5f8c4dcf3cd918d9a53e40..0b4699c9c71d905bc5242707b452c6cb0583aeda 100644 (file)
--- a/etc/zsh/.zshenv
+++ b/etc/zsh/.zshenv
@@ -3,21 +3,22 @@
 # XXX: only call after relevant vars have been set up, defined early so that
 #      below code can utilize it after they do so
 function _sev_zcleanup {
-    local x p y
+    local x y
 
+    function _sev_checkpid {
+        # return 1 if pid is a zsh process that isn't us
+        [[ $$ -eq $1 ]] || { ! kill -0 $1 2>/dev/null ||
+            [[ $(ps -aopid=,comm= | awk "\$1 == $1 { print \$2 }") != zsh ]] }
+    }
     # gpg forwarding
     if [[ -d $_sev_gpg_forward_dir && ( -z $1 || $1 == 'gpg-forward' ) ]] {
         # clean up forward dirs if its session is dead or we ask for it
         find $_sev_gpg_forward_dir -mindepth 1 -maxdepth 1 -type d |
           while {read -r x} {
-            # NOTE: the only way we can get here is if we have not been
-            #       forwarded before, if the user asks for it, or during
-            #       logout. if our own pid already has a dir, it is most likely
-            #       stale, the user wants it removed, or something is very
-            #       broken—in all 3 of these cases the best choice is remove it.
-            p=$(basename $x)
-            if {[[ -v _sev_gpg_forward_clean || $$ == $p ]] ||
-                    ! kill -0 $p 2>/dev/null} {
+            # NOTE: called before setup and on logout: remove the dir we
+            #       will be using (it's stale) or the dir we did use, and any
+            #       dead sessions if present
+            if (_sev_checkpid ${x:t}) {
                 find $x -mindepth 1 -maxdepth 1 | while {read -r y} {
                     # XXX: real dirs will stop unlink, consider it a feature
                     unlink $y
@@ -38,16 +39,16 @@ function _sev_zcleanup {
     #       after this function is called
     if [[ -d $_sev_tmp && ( -z $1 || $1 == 'tmp' ) ]] {
         # clean up tmp dirs if its session is dead or we ask for it
-        find $_sev_tmp -mindepth 1 -maxdepth 1 -name '.session.*' -type d |
+        find -L $_sev_tmp -mindepth 1 -maxdepth 1 -name '.session.*' -type d |
           while {read -r x} {
             # NOTE: same rationale as above
-            p=${$(basename $x)#.session.}
-            if {[[ -v _sev_tmp_clean || $$ == $p ]] ||
-                    ! kill -0 $p 2>/dev/null} {
+            if (_sev_checkpid ${${x:t}#.session.}) {
                 rm -rf $x
             }
         }
     }
+
+    unfunction _sev_checkpid
 }
 
 function _sev_setpath {
@@ -205,11 +206,13 @@ if [[ ! -v _sev_tmp ]] {
     _sev_zcleanup tmp
     # finally create our subdir for this session
     _t=$_sev_tmp/.session.$$
-    if ! mkdir -m700 $_t 2>/dev/null; then
+    # XXX: we probably shouldn't allow the use of an existing dir—tmp dir for
+    #      current pid should have been removed by zcleanup
+    if ([[ ! -d $_t ]] && ! mkdir -m700 $_t 2>/dev/null) {
         [[ -o interactive ]] &&
           print -P "%F{red}!!! Can't create session tmp subdir $_t, using $_sev_tmp%f"
         _t=$_sev_tmp
-    fi
+    }
     export _sev_tmp TMPDIR=$_t TEMPDIR=$_t TEMP=$_t TMP=$_t TMPPREFIX=$_t/zsh
     unset _t
 }