Index: generic/tclBasic.c
==================================================================
--- generic/tclBasic.c
+++ generic/tclBasic.c
@@ -4814,15 +4814,58 @@
     Namespace *currNsPtr = NULL;/* Used to check for and invoke any registered
 				 * unknown command handler for the current
 				 * namespace (TIP 181). */
     Namespace *savedNsPtr = NULL;
 
+    Tcl_Size qualLen;
+    const char *qualName = TclGetStringFromObj(objv[0], &qualLen);
+
     currNsPtr = varFramePtr->nsPtr;
-    if ((currNsPtr == NULL) || (currNsPtr->unknownHandlerPtr == NULL)) {
-	currNsPtr = iPtr->globalNsPtr;
-	if (currNsPtr == NULL) {
-	    Tcl_Panic("TEOV_NotFound: NULL global namespace pointer");
+    if ((currNsPtr == NULL) || (currNsPtr->unknownHandlerPtr == NULL) ||
+	(qualLen > 2 && memchr(qualName, ':', qualLen)) /* fast check for NS:: */
+    ) {
+	/*
+	 * first try to find namespace unknown handler of the namespace
+	 * of executed command if available:
+	 */
+	Namespace *altNsPtr, *dummyNsPtr;
+	const char *simpleName;
+
+	(void) TclGetNamespaceForQualName(interp, qualName, currNsPtr,
+	    TCL_FIND_IF_NOT_SIMPLE, &currNsPtr, &altNsPtr,
+	    &dummyNsPtr, &simpleName);
+	if (!simpleName) {
+	    goto globNS;
+	}
+	if (!currNsPtr || (currNsPtr == iPtr->globalNsPtr)) {
+	    if (!altNsPtr || (altNsPtr == iPtr->globalNsPtr)) {
+		goto globNS;
+	    }
+	    currNsPtr = altNsPtr;
+	}
+	while (currNsPtr->unknownHandlerPtr == NULL ||
+	    (currNsPtr->flags & (NS_DYING | NS_DEAD))
+	) {
+	    /* traverse to alive parent namespace containing handler */
+	    if (!(currNsPtr = currNsPtr->parentPtr) ||
+		 (currNsPtr == iPtr->globalNsPtr)
+	    ) {
+		/* continue from alternate NS if available */
+		if (!altNsPtr || (altNsPtr == iPtr->globalNsPtr)) {
+		    goto globNS;
+		}
+		currNsPtr = altNsPtr;
+		altNsPtr = NULL;
+		continue;
+	      globNS:
+		/* fallback to the global unknown */
+		currNsPtr = iPtr->globalNsPtr;
+		if (currNsPtr == NULL) {
+		    Tcl_Panic("TEOV_NotFound: NULL global namespace pointer");
+		}
+		break;
+	    }
 	}
     }
 
     /*
      * Check to see if the resolution namespace has lost its unknown handler.

Index: library/init.tcl
==================================================================
--- library/init.tcl
+++ library/init.tcl
@@ -116,10 +116,22 @@
 	}
 	namespace inscope ::tcl::clock [list namespace ensemble create -command \
 	    [uplevel 1 [list ::namespace origin [::lindex [info level 0] 0]]] \
 	    -map $cmdmap]
 	::tcl::unsupported::clock::configure -init-complete
+
+	# Auto-loading stubs for 'clock.tcl'
+
+	namespace inscope ::tcl::clock {
+	    proc _load_stubs args {
+		namespace unknown {}
+		::source -encoding utf-8 [::file join [info library] clock.tcl]
+		tailcall {*}$args
+	    }
+	    namespace unknown ::tcl::clock::_load_stubs
+	}
+
 	uplevel 1 [info level 0]
     }
 }
 
 # Conditionalize for presence of exec.

Index: library/tclIndex
==================================================================
--- library/tclIndex
+++ library/tclIndex
@@ -17,33 +17,10 @@
 set auto_index(::auto_mkindex_parser::childhook) [list ::tcl::Pkg::source [file join $dir auto.tcl]]
 set auto_index(::auto_mkindex_parser::command) [list ::tcl::Pkg::source [file join $dir auto.tcl]]
 set auto_index(::auto_mkindex_parser::commandInit) [list ::tcl::Pkg::source [file join $dir auto.tcl]]
 set auto_index(::auto_mkindex_parser::fullname) [list ::tcl::Pkg::source [file join $dir auto.tcl]]
 set auto_index(::auto_mkindex_parser::indexEntry) [list ::tcl::Pkg::source [file join $dir auto.tcl]]
-set auto_index(::tcl::clock::Initialize) [list ::tcl::Pkg::source [file join $dir clock.tcl]]
-set auto_index(::tcl::clock::mcget) [list ::tcl::Pkg::source [file join $dir clock.tcl]]
-set auto_index(::tcl::clock::mcMerge) [list ::tcl::Pkg::source [file join $dir clock.tcl]]
-set auto_index(::tcl::clock::GetSystemLocale) [list ::tcl::Pkg::source [file join $dir clock.tcl]]
-set auto_index(::tcl::clock::EnterLocale) [list ::tcl::Pkg::source [file join $dir clock.tcl]]
-set auto_index(::tcl::clock::_hasRegistry) [list ::tcl::Pkg::source [file join $dir clock.tcl]]
-set auto_index(::tcl::clock::LoadWindowsDateTimeFormats) [list ::tcl::Pkg::source [file join $dir clock.tcl]]
-set auto_index(::tcl::clock::LocalizeFormat) [list ::tcl::Pkg::source [file join $dir clock.tcl]]
-set auto_index(::tcl::clock::GetSystemTimeZone) [list ::tcl::Pkg::source [file join $dir clock.tcl]]
-set auto_index(::tcl::clock::SetupTimeZone) [list ::tcl::Pkg::source [file join $dir clock.tcl]]
-set auto_index(::tcl::clock::GuessWindowsTimeZone) [list ::tcl::Pkg::source [file join $dir clock.tcl]]
-set auto_index(::tcl::clock::LoadTimeZoneFile) [list ::tcl::Pkg::source [file join $dir clock.tcl]]
-set auto_index(::tcl::clock::LoadZoneinfoFile) [list ::tcl::Pkg::source [file join $dir clock.tcl]]
-set auto_index(::tcl::clock::ReadZoneinfoFile) [list ::tcl::Pkg::source [file join $dir clock.tcl]]
-set auto_index(::tcl::clock::ParsePosixTimeZone) [list ::tcl::Pkg::source [file join $dir clock.tcl]]
-set auto_index(::tcl::clock::ProcessPosixTimeZone) [list ::tcl::Pkg::source [file join $dir clock.tcl]]
-set auto_index(::tcl::clock::DeterminePosixDSTTime) [list ::tcl::Pkg::source [file join $dir clock.tcl]]
-set auto_index(::tcl::clock::GetJulianDayFromEraYearDay) [list ::tcl::Pkg::source [file join $dir clock.tcl]]
-set auto_index(::tcl::clock::GetJulianDayFromEraYearMonthWeekDay) [list ::tcl::Pkg::source [file join $dir clock.tcl]]
-set auto_index(::tcl::clock::IsGregorianLeapYear) [list ::tcl::Pkg::source [file join $dir clock.tcl]]
-set auto_index(::tcl::clock::WeekdayOnOrBefore) [list ::tcl::Pkg::source [file join $dir clock.tcl]]
-set auto_index(::tcl::clock::ChangeCurrentLocale) [list ::tcl::Pkg::source [file join $dir clock.tcl]]
-set auto_index(::tcl::clock::ClearCaches) [list ::tcl::Pkg::source [file join $dir clock.tcl]]
 set auto_index(foreachLine) [list ::tcl::Pkg::source [file join $dir foreachline.tcl]]
 set auto_index(::tcl::history) [list ::tcl::Pkg::source [file join $dir history.tcl]]
 set auto_index(history) [list ::tcl::Pkg::source [file join $dir history.tcl]]
 set auto_index(::tcl::HistAdd) [list ::tcl::Pkg::source [file join $dir history.tcl]]
 set auto_index(::tcl::HistKeep) [list ::tcl::Pkg::source [file join $dir history.tcl]]

Index: tests/namespace.test
==================================================================
--- tests/namespace.test
+++ tests/namespace.test
@@ -3122,10 +3122,52 @@
 	namespace unknown
     }
 } -cleanup {
     namespace delete foo
 } -result ok
+test namespace-52.13 {unknown: invocation outside of NS doesn't evade namespace unknown, bug 910d67a229fe7f65} -body {
+    namespace eval ::foo::bar {
+	proc _unknown args {list ::foo:bar:_unknown [uplevel {namespace current}] $args}
+	namespace unknown [namespace current]::_unknown
+    }
+    list [namespace inscope ::foo::bar {xxx}] [namespace inscope ::foo {bar::xxx}] [::foo::bar::xxx] [namespace inscope :: {foo::bar::xxx}]
+} -cleanup {
+    namespace delete ::foo
+} -result {{::foo:bar:_unknown ::foo::bar xxx} {::foo:bar:_unknown ::foo bar::xxx} {::foo:bar:_unknown :: ::foo::bar::xxx} {::foo:bar:_unknown :: foo::bar::xxx}}
+test namespace-52.14 {unknown: invocation outside of NS doesn't evade namespace unknown for command with sub-NS, bug 910d67a229fe7f65} -body {
+    namespace eval ::foo::bar {
+	proc _unknown args {list ::foo:bar:_unknown [uplevel {namespace current}] $args}
+	namespace unknown [namespace current]::_unknown
+    }
+    set res {}
+    lappend res [namespace inscope ::foo::bar {xxx::yyy}] [namespace inscope ::foo {bar::xxx::yyy}] [::foo::bar::xxx::yyy] [namespace inscope :: {foo::bar::xxx::yyy}]
+    # now with existsing ::foo::bar::xxx, but without unknown handler inside (only parent ::foo::bar has a handler):
+    namespace eval ::foo::bar::xxx {}
+    lappend res [namespace inscope ::foo::bar {xxx::yyy}] [namespace inscope ::foo {bar::xxx::yyy}] [::foo::bar::xxx::yyy] [namespace inscope :: {foo::bar::xxx::yyy}]
+} -cleanup {
+    namespace delete ::foo
+    unset -nocomplain res
+} -result [lrepeat 2 \
+  {::foo:bar:_unknown ::foo::bar xxx::yyy} {::foo:bar:_unknown ::foo bar::xxx::yyy} {::foo:bar:_unknown :: ::foo::bar::xxx::yyy} {::foo:bar:_unknown :: foo::bar::xxx::yyy}
+]
+test namespace-52.14 {unknown: it must consider alternate search path (relative global NS), bug 910d67a229fe7f65} -body {
+    namespace eval ::foo::bar {}
+    namespace eval ::xxx::yyy {
+	proc _unknown args {list ::xxx:yyy:_unknown [uplevel {namespace current}] $args}
+	namespace unknown [namespace current]::_unknown
+    }
+    set res {}
+    lappend res [namespace inscope ::foo::bar {xxx::yyy::cmd}] [namespace inscope ::foo {xxx::yyy::cmd}]
+    namespace eval ::foo::bar::xxx {}
+    lappend res [namespace inscope ::foo::bar {xxx::yyy::cmd}] [namespace inscope ::foo {xxx::yyy::cmd}]
+    namespace eval ::foo::bar::xxx::yyy {}
+    lappend res [namespace inscope ::foo::bar {xxx::yyy::cmd}] [namespace inscope ::foo {xxx::yyy::cmd}]
+} -cleanup {
+    namespace delete ::foo
+    namespace delete ::xxx
+    unset -nocomplain res
+} -result [lrepeat 3 {::xxx:yyy:_unknown ::foo::bar xxx::yyy::cmd} {::xxx:yyy:_unknown ::foo xxx::yyy::cmd}]
 
 # TIP 314 - ensembles with parameters
 test namespace-53.1 {ensembles: parameters} {
     namespace eval ns {
 	namespace export x