Restore dependent reload list when an evaluation is rolled back

When the unload of a module triggers the unload phase of several
dependent modules and one of them fails, the evaluation is rolled back
but the dependent reload list keeps the modules queued before the
failure. Their properties were never saved as the unload phase stopped
before reaching them. If the sequence then continues, like a switch
with switch_unload absent from abort_on_error, the reload phase looks up
these missing properties and raises an internal Tcl error.

Save the dependent reload list and the saved properties of reloading
modules along with the other settings pushed before an evaluation, so a
rollback restores them to their state prior the failed evaluation.
Dependents restored in the loaded environment by this rollback are thus
not reloaded anymore.

Assisted-by: Claude:claude-fable-5-1
Signed-off-by: Adrien Cotte <adrien.cotte@asplus.fr>
Signed-off-by: Xavier Delaruelle <xavier.delaruelle@cea.fr>

Author: adrien-cotte

NEWS.rst

@@ -267,6 +267,11 @@ Modules 5.7.0 (not yet released)
 * Keep non-sticky requirements of sticky modules loaded during a
   :subcmd:`purge` and explicitly report why their unload is skipped according
   to the :mconfig:`sticky_purge` configuration. (fix issue #582)
+* Fix internal error raised by :subcmd:`switch` sub-command when the unload
+  of the switched-off module fails after some of its dependent modules were
+  unloaded for reload, and switch sequence continues as ``switch_unload`` is
+  not set in :mconfig:`abort_on_error`. Dependent modules restored by the
+  failed unload are not reloaded anymore.
 
 .. _CVE-2026-85013: https://github.com/envmodules/modules/security/advisories/GHSA-8hrw-p88g-qhmg
 

tcl/modeval.tcl

@@ -593,7 +593,7 @@ proc pushSettings {} {
       g_moduleNPODepend g_dependNPOHash g_prereqViolation\
       g_prereqNPOViolation g_conflictViolation g_moduleUnmetDep\
       g_unmetDepHash g_moduleEval g_moduleHiddenEval g_scanModuleVariant\
-      g_savedLoReqOfReloadMod g_savedLoReqOfUnloadMod\
+      g_savedLoReqOfReloadMod g_savedLoReqOfUnloadMod g_savedPropsOfReloadMod\
       g_loadedModulePrereqPath g_tagHash g_loadedByModroot g_modrootByLoaded\
       g_loadedModulePosition g_modrootByLoadedConflict\
       g_loadedConflictByModroot} {
@@ -605,7 +605,7 @@ proc pushSettings {} {
 
    # save non-array variable and indication if it was set
    foreach var {g_changeDir g_stdoutPuts g_prestdoutPuts g_return_text\
-      g_uReqUnFromDepReList} {
+      g_uReqUnFromDepReList g_depReList} {
       ##nagelfar ignore #2 Badly formed if statement
       lappend save_var $var {*}[if {[info exists ::$var]} {list 1 [set\
          ::$var]} {list 0 {}}]

testsuite/modules.50-cmds/616-abort_on_error-switch.exp

@@ -878,6 +878,34 @@ append ts_depre_unload_error_force [msg_top_switch foo/1.0 setenv/1.0 {} {} {} {
 testouterr_cmd bash {switch --force foo/1.0 setenv/1.0} $ans_unload_fail_depre_force $ts_depre_unload_error_force
 
 
+# another dependent module was unloaded prior failing dependent unload
+setenv_loaded_module [list foo/1.0 lerr/1.0 err/1.0] [list $mp/foo/1.0 $mp/lerr/1.0 $mp/err/1.0]
+setenv_var __MODULES_LMPREREQ lerr/1.0&foo:err/1.0&err/1.0|foo
+
+set ans_unload_fail_depre_other_continue [list]
+lappend ans_unload_fail_depre_other_continue [list set TS1 {}]
+lappend ans_unload_fail_depre_other_continue [list set TS2 {}]
+lappend ans_unload_fail_depre_other_continue [list set _LMFILES_ $mp/foo/1.0:$mp/lerr/1.0:$mp/err/1.0:$mp/setenv/1.0]
+lappend ans_unload_fail_depre_other_continue [list set LOADEDMODULES foo/1.0:lerr/1.0:err/1.0:setenv/1.0]
+lappend ans_unload_fail_depre_other_continue [list ERR]
+
+testouterr_cmd bash {switch foo/1.0 setenv/1.0} $ans_unload_fail_depre_other_continue $ts_depre_unload_error
+
+set ans_unload_fail_depre_other_force [list]
+lappend ans_unload_fail_depre_other_force [list set TS1 {}]
+lappend ans_unload_fail_depre_other_force [list set TS2 {}]
+lappend ans_unload_fail_depre_other_force [list set __MODULES_LMPREREQ err/1.0&err/1.0|foo]
+lappend ans_unload_fail_depre_other_force [list set _LMFILES_ $mp/setenv/1.0:$mp/err/1.0]
+lappend ans_unload_fail_depre_other_force [list set LOADEDMODULES setenv/1.0:err/1.0]
+
+set ts_depre_unload_error_other_force [msg_unload err/1.0 [msg_modwarn msg {error msg} $mp/err/1.0 2 {} {} {} $custom_error_trace]]\n\n
+append ts_depre_unload_error_other_force [msg_top_switch foo/1.0 setenv/1.0 {} {} {} {} [list {err/1.0 lerr/1.0} err/1.0]]
+testouterr_cmd bash {switch --force foo/1.0 setenv/1.0} $ans_unload_fail_depre_other_force $ts_depre_unload_error_other_force
+
+setenv_loaded_module [list foo/1.0 err/1.0] [list $mp/foo/1.0 $mp/err/1.0]
+setenv_var __MODULES_LMPREREQ err/1.0&err/1.0|foo
+
+
 setenv_var TESTSUITE_ABORT_ON_ERROR depre_unload_bad
 
 set ts_depre_unload_bad [msg_unload err/1.0 [msg_moderr {invalid command name "bad"} bad $mp/err/1.0 2 {} {} {} $custom_error_trace]]\n\n