Merge 8.6

21 files changed, 209 insertions, 66 deletions

diff --git a/.github/workflows/linux-build.yml b/.github/workflows/linux-build.yml
index db46cfd..a4fd7b3 100644
--- a/.github/workflows/linux-build.yml
+++ b/.github/workflows/linux-build.yml
@@ -1,37 +1,45 @@
 name: Linux Build and Test
 on: [push]
 jobs:
-  build:
+  gcc:
     runs-on: ubuntu-latest
+    strategy:
+      matrix:
+        symbols:
+          - "no"
+          - "mem"
+          - "all"
+    defaults:
+      run:
+        shell: bash
+        working-directory: unix
     steps:
       - name: Checkout
         uses: actions/checkout@v2
-      - name: Configure
-        working-directory: unix
+      - name: Configure (symbols=${{ matrix.symbols }})
         run: |
           mkdir "${HOME}/install dir"
           ./configure ${CFGOPT} "--prefix=$HOME/install dir" || (cat config.log && exit 1)
+        env:
+          CFGOPT: --enable-symbols=${{ matrix.symbols }}
+      - name: Prepare
+        run: touch tclStubInit.c tclOOStubInit.c
+        working-directory: generic
       - name: Build
-        working-directory: unix
         run: |
           make all
       - name: Build Test Harness
-        working-directory: unix
         run: |
           make tcltest
       - name: Run Tests
-        working-directory: unix
         run: |
           make test
       - name: Test-Drive Installation
-        working-directory: unix
         run: |
           make install
       - name: Create Distribution Package
-        working-directory: unix
         run: |
           make dist
       - name: Convert Documentation to HTML
-        working-directory: unix
         run: |
           make html-tcl
diff --git a/.github/workflows/mac-build.yml b/.github/workflows/mac-build.yml
new file mode 100644
index 0000000..c78f882
--- /dev/null
+++ b/.github/workflows/mac-build.yml
@@ -0,0 +1,61 @@
+name: macOS Build and Test
+on: [push]
+jobs:
+  with-Xcode:
+    runs-on: macos-latest
+    defaults:
+      run:
+        shell: bash
+        working-directory: macosx
+    steps:
+      - name: Checkout
+        uses: actions/checkout@v2
+      - name: Prepare
+        run: touch tclStubInit.c tclOOStubInit.c
+        working-directory: generic
+      - name: Build
+        run: make all
+      - name: Run Tests
+        run: make test styles=develop
+        env:
+          ERROR_ON_FAILURES: 1
+          MAC_CI: 1
+  Unix-like:
+    runs-on: macos-latest
+    strategy:
+      matrix:
+        symbols:
+          - "no"
+          - "mem"
+        dtrace:
+          - "no"
+          - "yes"
+    defaults:
+      run:
+        shell: bash
+        working-directory: unix
+    steps:
+      - name: Checkout
+        uses: actions/checkout@v2
+      - name: Prepare
+        run: |
+          touch tclStubInit.c tclOOStubInit.c
+          mkdir "$HOME/install dir"
+        working-directory: generic
+      - name: Configure (symbols=${{ matrix.symbols }} dtrace=${{ matrix.dtrace }})
+        # Note that macOS is always a 64 bit platform
+        run: ./configure --enable-64bit ${CFGOPT} "--prefix=$HOME/install dir" || (cat config.log && exit 1)
+        env:
+          CFGOPT: --enable-symbols=${{ matrix.symbols }} --enable-dtrace=${{ matrix.dtrace }}
+      - name: Build
+        run: |
+          make all tcltest
+      - name: Run Tests
+        run: |
+          make test
+        env:
+          ERROR_ON_FAILURES: 1
+          MAC_CI: 1
+      - name: Trial Installation
+        run: |
+          make install
diff --git a/.github/workflows/win-build.yml b/.github/workflows/win-build.yml
index 652b34a..9c3d76c 100644
--- a/.github/workflows/win-build.yml
+++ b/.github/workflows/win-build.yml
@@ -1,22 +1,75 @@
 name: Windows Build and Test
 on: [push]
 jobs:
-  build:
+  MSVC:
     runs-on: windows-latest
+    defaults:
+      run:
+        shell: powershell
+        working-directory: win
+    # Using powershell means we need to explicitly stop on failure
     steps:
       - name: Checkout
         uses: actions/checkout@v2
       - name: Init MSVC
         uses: ilammy/msvc-dev-cmd@v1
       - name: Build
-        working-directory: win
         run: |
-          nmake -f makefile.vc all
+          &nmake -f makefile.vc all
+          if ($lastexitcode -ne 0) {
+             throw "nmake exit code: $lastexitcode"
+          }
       - name: Build Test Harness
-        working-directory: win
         run: |
-          nmake -f makefile.vc tcltest
+          &nmake -f makefile.vc tcltest
+          if ($lastexitcode -ne 0) {
+             throw "nmake exit code: $lastexitcode"
+          }
       - name: Run Tests
+        run: |
+          &nmake -f makefile.vc test
+          if ($lastexitcode -ne 0) {
+             throw "nmake exit code: $lastexitcode"
+          }
+        env:
+          ERROR_ON_FAILURES: 1
+          CI_BUILD_WITH_MSVC: 1
+  MSYS-gcc:
+    runs-on: windows-latest
+    defaults:
+      run:
+        shell: bash
         working-directory: win
+    strategy:
+      matrix:
+        symbols:
+          - "no"
+          - "mem"
+          - "all"
+    # Using powershell means we need to explicitly stop on failure
+    steps:
+      - name: Checkout
+        uses: actions/checkout@v2
+      - name: Install MSYS2 and Make
+        run: choco install msys2 make
+      - name: Prepare
+        run: |
+          touch tclStubInit.c tclOOStubInit.c
+          mkdir "${HOME}/install dir"
+        working-directory: generic
+      - name: Configure (symbols=${{ matrix.symbols }})
         run: |
-          nmake -f makefile.vc test
+          ./configure ${CFGOPT} "--prefix=$HOME/install dir" || (cat config.log && exit 1)
+        env:
+          CFGOPT: --enable-64bit --enable-symbols=${{ matrix.symbols }}
+      - name: Build
+        run: make all
+      - name: Build Test Harness
+        run: make tcltest
+      - name: Run Tests
+        run: make test
+        env:
+          ERROR_ON_FAILURES: 1
+
+# If you add builds with Wine, be sure to define the environment variable
+# CI_USING_WINE when running them so that broken tests know not to run.
diff --git a/README.md b/README.md
index 56db098..905b32e 100644
--- a/README.md
+++ b/README.md
@@ -8,14 +8,17 @@ site](https://sourceforge.net/projects/tcl/files/Tcl/).
 8.6.10
 [![Build Status](https://github.com/tcltk/tcl/workflows/Linux%20Build%20and%20Test/badge.svg?branch=core-8-6-branch)](https://github.com/tcltk/tcl/actions?query=workflow%3A%22Linux+Build+and+Test%22+branch%3Acore-8-6-branch)
 [![Build Status](https://github.com/tcltk/tcl/workflows/Windows%20Build%20and%20Test/badge.svg?branch=core-8-6-branch)](https://github.com/tcltk/tcl/actions?query=workflow%3A%22Windows+Build+and+Test%22+branch%3Acore-8-6-branch)
+[![Build Status](https://github.com/tcltk/tcl/workflows/macOS%20Build%20and%20Test/badge.svg?branch=core-8-6-branch)](https://github.com/tcltk/tcl/actions?query=workflow%3A%22macOS+Build+and+Test%22+branch%3Acore-8-6-branch)
 <br>
 8.7a4
 [![Build Status](https://github.com/tcltk/tcl/workflows/Linux%20Build%20and%20Test/badge.svg?branch=core-8-branch)](https://github.com/tcltk/tcl/actions?query=workflow%3A%22Linux+Build+and+Test%22+branch%3Acore-8-branch)
 [![Build Status](https://github.com/tcltk/tcl/workflows/Windows%20Build%20and%20Test/badge.svg?branch=core-8-branch)](https://github.com/tcltk/tcl/actions?query=workflow%3A%22Windows+Build+and+Test%22+branch%3Acore-8-branch)
+[![Build Status](https://github.com/tcltk/tcl/workflows/macOS%20Build%20and%20Test/badge.svg?branch=core-8-branch)](https://github.com/tcltk/tcl/actions?query=workflow%3A%22macOS+Build+and+Test%22+branch%3Acore-8-branch)
 <br>
 9.0a2
 [![Build Status](https://github.com/tcltk/tcl/workflows/Linux%20Build%20and%20Test/badge.svg?branch=main)](https://github.com/tcltk/tcl/actions?query=workflow%3A%22Linux+Build+and+Test%22+branch%3Amain)
 [![Build Status](https://github.com/tcltk/tcl/workflows/Windows%20Build%20and%20Test/badge.svg?branch=main)](https://github.com/tcltk/tcl/actions?query=workflow%3A%22Windows+Build+and+Test%22+branch%3Amain)
+[![Build Status](https://github.com/tcltk/tcl/workflows/macOS%20Build%20and%20Test/badge.svg?branch=main)](https://github.com/tcltk/tcl/actions?query=workflow%3A%22macOS+Build+and+Test%22+branch%3Amain)
 
 ## Contents
  1. [Introduction](#intro)
diff --git a/tests/async.test b/tests/async.test
index ad058a0..f57063f 100644
--- a/tests/async.test
+++ b/tests/async.test
@@ -20,7 +20,7 @@ if {"::tcltest" ni [namespace children]} {
 catch [list package require -exact Tcltest [info patchlevel]]
 
 testConstraint testasync [llength [info commands testasync]]
-testConstraint knownMsvcBug [expr {![info exists ::env(TRAVIS_OS_NAME)] || ![string match windows $::env(TRAVIS_OS_NAME)]}]
+testConstraint knownMsvcBug [expr {![info exists ::env(CI_BUILD_WITH_MSVC)]}]
 
 proc async1 {result code} {
     global aresult acode
diff --git a/tests/chanio.test b/tests/chanio.test
index 858db7f..434300b 100644
--- a/tests/chanio.test
+++ b/tests/chanio.test
@@ -47,7 +47,8 @@ namespace eval ::tcl::test::io {
     testConstraint testchannelevent [llength [info commands testchannelevent]]
     testConstraint testmainthread   [llength [info commands testmainthread]]
     testConstraint testservicemode  [llength [info commands testservicemode]]
-    testConstraint knownMsvcBug [expr {![info exists ::env(TRAVIS_OS_NAME)] || ![string match windows $::env(TRAVIS_OS_NAME)]}]
+    testConstraint notWinCI       [expr {
+	$::tcl_platform(platform) ne "windows" || ![info exists ::env(CI)]}]
     testConstraint notOSX [expr {$::tcl_platform(os) ne "Darwin"}]
 
     # You need a *very* special environment to do some tests.  In particular,
@@ -1886,7 +1887,7 @@ test chan-io-20.3 {Tcl_CreateChannel: initial settings} -constraints {unix} -bod
 } -result {{{} {}} {auto lf}}
 test chan-io-20.5 {Tcl_CreateChannel: install channel in empty slot} -setup {
     set path(stdout) [makeFile {} stdout]
-} -constraints {stdio knownMsvcBug} -body {
+} -constraints {stdio notWinCI} -body {
     set f [open $path(script) w]
     chan puts -nonewline $f {
 	chan close stdout
@@ -2796,7 +2797,7 @@ test chan-io-29.34 {Tcl_Chan Close, async flush on chan close, using sockets} -s
 	    chan puts $s $l
 	}
     }
-} -constraints {socket tempNotMac fileevent knownMsvcBug} -body {
+} -constraints {socket tempNotMac fileevent notWinCI} -body {
     proc accept {s a p} {
 	variable x
 	chan event $s readable [namespace code [list readit $s]]
diff --git a/tests/cmdAH.test b/tests/cmdAH.test
index 97b2e91..74fd387 100644
--- a/tests/cmdAH.test
+++ b/tests/cmdAH.test
@@ -30,7 +30,7 @@ testConstraint linkDirectory [expr {
     ($::tcl_platform(osVersion) >= 5.0
      && [lindex [file system [temporaryDirectory]] 1] eq "NTFS")
 }]
-testConstraint notWine [expr {$::tcl_platform(platform) ne "windows" || ![info exists ::env(TRAVIS_OS_NAME)] || ![string match linux $::env(TRAVIS_OS_NAME)]}]
+testConstraint notWine [expr {![info exists ::env(CI_USING_WINE)]}]
 
 global env
 set cmdAHwd [pwd]
diff --git a/tests/exec.test b/tests/exec.test
index 5082393..84cfc17 100644
--- a/tests/exec.test
+++ b/tests/exec.test
@@ -26,7 +26,8 @@ package require tcltests
 # All tests require the "exec" command.
 # Skip them if exec is not defined.
 testConstraint exec [llength [info commands exec]]
-testConstraint noosx [expr {![info exists ::env(TRAVIS_OSX_IMAGE)] || ![string match xcode* $::env(TRAVIS_OSX_IMAGE)]}]
+# Some skips when running in a macOS CI environment
+testConstraint noosxCI [expr {![info exists ::env(MAC_CI)]}]
 
 unset -nocomplain path
 
@@ -673,7 +674,9 @@ test exec-18.2 {exec cat deals with weird file names} -body {
 # Note that this test cannot be adapted to work on Windows; that platform has
 # no kernel support for an analog of O_APPEND. OTOH, that means we can assume
 # that there is a POSIX shell...
-test exec-19.1 {exec >> uses O_APPEND} -constraints {exec unix notValgrind noosx} -setup {
+#
+# This test also fails in some cases when building with macOS
+test exec-19.1 {exec >> uses O_APPEND} -constraints {exec unix notValgrind noosxCI} -setup {
     set tmpfile [makeFile {0} tmpfile.exec-19.1]
 } -body {
     # Note that we have to allow for the current contents of the temporary
diff --git a/tests/fCmd.test b/tests/fCmd.test
index a1e0a6e..b4383db 100644
--- a/tests/fCmd.test
+++ b/tests/fCmd.test
@@ -41,7 +41,7 @@ if {[testConstraint win]} {
 	testConstraint reg 1
     }
 }
-testConstraint notWine [expr {$::tcl_platform(platform) ne "windows" || ![info exists ::env(TRAVIS_OS_NAME)] || ![string match linux $::env(TRAVIS_OS_NAME)]}]
+testConstraint notCI [expr {![info exists ::env(CI)] || !$::env(CI)}]
 
 set tmpspace /tmp;# default value
 # Find a group that exists on this Unix system, or else skip tests that
@@ -79,6 +79,7 @@ testConstraint darwin9 [expr {
     && [package vsatisfies 1.$::tcl_platform(osVersion) 1.9]
 }]
 testConstraint notDarwin9 [expr {![testConstraint darwin9]}]
+testConstraint notContinuousIntegration [expr {![info exists ::env(CI)]}]
 
 testConstraint fileSharing 0
 testConstraint notFileSharing 1
@@ -2581,7 +2582,9 @@ test fCmd-30.2 {file readable on 'NTUSER.DAT'} -constraints {win notWine} -body
           && [file exists $env(USERPROFILE)/NTUSER.DAT]
           && [file readable $env(USERPROFILE)/NTUSER.DAT]}
 } -result {1}
-test fCmd-30.3 {file readable on 'pagefile.sys'} -constraints {win notWine} -body {
+# At least one CI environment (GitHub Actions) is set up with the page file in
+# an unusual location; skip the test if that is so.
+test fCmd-30.3 {file readable on 'pagefile.sys'} -constraints {win notCI} -body {
     set r {}
     if {[info exists env(SystemDrive)]} {
         set path $env(SystemDrive)/pagefile.sys
diff --git a/tests/fileName.test b/tests/fileName.test
index ac93383..0525ec5 100644
--- a/tests/fileName.test
+++ b/tests/fileName.test
@@ -31,7 +31,7 @@ if {[testConstraint win]} {
     testConstraint symbolicLinkFile 0
     testConstraint sharedCdrive [expr {![catch {cd //[info hostname]/c}]}]
 }
-testConstraint notWine [expr {$::tcl_platform(platform) ne "windows" || ![info exists ::env(TRAVIS_OS_NAME)] || ![string match linux $::env(TRAVIS_OS_NAME)]}]
+testConstraint notWine [expr {![info exists ::env(CI_USING_WINE)]}]
 # This match compares the first two words of the result. If the wanted result
 # is "equal", then this is successful if the words are equal. If the wanted
 # result is "not equal", then this is successful if the words are different.
diff --git a/tests/fileSystem.test b/tests/fileSystem.test
index 19066ee..c60d092 100644
--- a/tests/fileSystem.test
+++ b/tests/fileSystem.test
@@ -37,7 +37,9 @@ catch {
 testConstraint testfilesystem  	    [llength [info commands ::testfilesystem]]
 testConstraint testsetplatform 	    [llength [info commands ::testsetplatform]]
 testConstraint testsimplefilesystem [llength [info commands ::testsimplefilesystem]]
-testConstraint knownMsvcBug [expr {![info exists ::env(TRAVIS_OS_NAME)] || ![string match windows $::env(TRAVIS_OS_NAME)]}]
+# Some things fail under all Continuous Integration systems for subtle reasons
+# such as CI often running with elevated privileges in a container.
+testConstraint notInCIenv           [expr {![info exists ::env(CI)]}]
 
 cd [tcltest::temporaryDirectory]
 makeFile "test file" gorp.file
@@ -316,7 +318,7 @@ test filesystem-1.37 {file normalisation with '/./'} -body {
 } -match regexp -result {^(?:[^/]|/(?:[^/]|$))+$}
 test filesystem-1.38 {file normalisation with volume relative} -setup {
     set dir [pwd]
-} -constraints {win moreThanOneDrive knownMsvcBug} -body {
+} -constraints {win moreThanOneDrive notInCIenv} -body {
     set path "[string range [lindex $drives 0] 0 1]foo"
     cd [lindex $drives 1]
     file norm $path
diff --git a/tests/format.test b/tests/format.test
index 8d6fd82..44fa64e 100644
--- a/tests/format.test
+++ b/tests/format.test
@@ -20,7 +20,10 @@ testConstraint longIs32bit [expr {$tcl_platform(wordSize) == 4}]
 testConstraint longIs64bit [expr {$tcl_platform(wordSize) == 8}]
 testConstraint wideIs64bit [expr {wide(0x8000000000000000) < 0}]
 testConstraint pointerIs64bit [expr {$tcl_platform(pointerSize) >= 8}]
-testConstraint knownMsvcBug [expr {![info exists ::env(TRAVIS_OS_NAME)] || ![string match windows $::env(TRAVIS_OS_NAME)]}]
+# MSVC uses a broken libc that gets sprintf("%g") wrong. This is a pain
+# particularly in Continuous Integration, and there isn't anything much we can
+# do about it.
+testConstraint knownMsvcBug [expr {![info exists ::env(CI_BUILD_WITH_MSVC)]}]
 
 test format-1.1 {integer formatting} {
     format "%*d %d %d %d" 6 34 16923 -12 -1
diff --git a/tests/httpcookie.test b/tests/httpcookie.test
index ca54073..38a18bb 100644
--- a/tests/httpcookie.test
+++ b/tests/httpcookie.test
@@ -16,11 +16,8 @@ if {"::tcltest" ni [namespace children]} {
 
 ::tcltest::loadTestedCommands
 
-testConstraint notOSXtravis [apply {{} {
-    upvar 1 env(TRAVIS_OSX_IMAGE) travis
-    return [expr {![info exists travis] || ![string match xcode* $travis]}]
-}}]
-testConstraint sqlite3 [expr {[testConstraint notOSXtravis] && ![catch {
+testConstraint notMacCI [expr {![info exists ::env(MAC_CI)]}]
+testConstraint sqlite3 [expr {[testConstraint notMacCI] && ![catch {
     package require sqlite3
 }]}]
 testConstraint cookiejar [expr {[testConstraint sqlite3] && ![catch {
diff --git a/tests/io.test b/tests/io.test
index a3e3b6f..a70c747 100644
--- a/tests/io.test
+++ b/tests/io.test
@@ -43,7 +43,10 @@ testConstraint testchannelevent [llength [info commands testchannelevent]]
 testConstraint testmainthread   [llength [info commands testmainthread]]
 testConstraint testobj		[llength [info commands testobj]]
 testConstraint testservicemode  [llength [info commands testservicemode]]
-testConstraint knownMsvcBug [expr {![info exists ::env(TRAVIS_OS_NAME)] || ![string match windows $::env(TRAVIS_OS_NAME)]}]
+# Some things fail under Windows in Continuous Integration systems for subtle
+# reasons such as CI often running with elevated privileges in a container.
+testConstraint notWinCI [expr {
+    $::tcl_platform(platform) ne "windows" || ![info exists ::env(CI)]}]
 testConstraint notOSX [expr {$::tcl_platform(os) ne "Darwin"}]
 
 # You need a *very* special environment to do some tests.  In
@@ -2230,7 +2233,7 @@ test io-27.5 {FlushChannel, implicit flush when buffer fills and on close} \
 set path(pipe)   [makeFile {} pipe]
 set path(output) [makeFile {} output]
 test io-27.6 {FlushChannel, async flushing, async close} \
-	{stdio asyncPipeClose knownMsvcBug} {
+	{stdio asyncPipeClose notWinCI} {
     # This test may fail on old Unix systems (seen on IRIX64 6.5) with
     # obsolete gettimeofday() calls.  See Tcl Bugs 3530533, 1942197.
     file delete $path(pipe)
@@ -2834,7 +2837,7 @@ test io-29.31 {Tcl_WriteChars, background flush} stdio {
     set result
 } ok
 test io-29.32 {Tcl_WriteChars, background flush to slow reader} \
-	{stdio asyncPipeClose knownMsvcBug} {
+	{stdio asyncPipeClose notWinCI} {
     # This test may fail on old Unix systems (seen on IRIX64 6.5) with
     # obsolete gettimeofday() calls.  See Tcl Bugs 3530533, 1942197.
     file delete $path(pipe)
@@ -8132,7 +8135,7 @@ test io-53.17 {[7c187a3773] MBWrite: proper inQueueTail handling} -setup {
     removeFile out
 } -result {line 100 line}
 
-test io-54.1 {Recursive channel events} {socket fileevent knownMsvcBug} {
+test io-54.1 {Recursive channel events} {socket fileevent notWinCI} {
     # This test checks to see if file events are delivered during recursive
     # event loops when there is buffered data on the channel.
 
diff --git a/tests/registry.test b/tests/registry.test
index dbf4575..c1673b5 100644
--- a/tests/registry.test
+++ b/tests/registry.test
@@ -24,7 +24,7 @@ if {[testConstraint win]} {
 	testConstraint reg 1
     }
 }
-testConstraint notWine [expr {$::tcl_platform(platform) ne "windows" || ![info exists ::env(TRAVIS_OS_NAME)] || ![string match linux $::env(TRAVIS_OS_NAME)]}]
+testConstraint notWine [expr {![info exists ::env(CI_USING_WINE)]}]
 
 # determine the current locale
 testConstraint english [expr {
diff --git a/tests/socket.test b/tests/socket.test
index 759008f..9d2e5eb 100644
--- a/tests/socket.test
+++ b/tests/socket.test
@@ -69,15 +69,17 @@ if {"::tcltest" ni [namespace children]} {
 catch [list package require -exact Tcltest [info patchlevel]]
 ::tcltest::loadTestedCommands
 
-if {[info exists ::env(TRAVIS_OSX_IMAGE)] && [string match xcode* $::env(TRAVIS_OSX_IMAGE)]} {
+# A bad interaction between socket creation, macOS, and unattended CI
+# environments make this whole file impractical to run; too many weird hangs.
+if {[info exists ::env(MAC_CI)]} {
     return
 }
-testConstraint notWine [expr {$::tcl_platform(platform) ne "windows" || ![info exists ::env(TRAVIS_OS_NAME)] || ![string match linux $::env(TRAVIS_OS_NAME)]}]
+testConstraint notWine [expr {![info exists ::env(CI_USING_WINE)]}]
 
 # Some tests require the Thread package or exec command
 testConstraint thread [expr {0 == [catch {package require Thread 2.7-}]}]
 testConstraint exec [llength [info commands exec]]
-testConstraint knownMsvcBug [expr {![info exists ::env(TRAVIS_OS_NAME)] || ![string match windows $::env(TRAVIS_OS_NAME)]}]
+testConstraint knownMsvcBug [expr {![info exists ::env(CI_BUILD_WITH_MSVC)]}]
 
 # Produce a random port number in the Dynamic/Private range
 # from 49152 through 65535.
diff --git a/tests/winDde.test b/tests/winDde.test
index 421578b..9d15357 100644
--- a/tests/winDde.test
+++ b/tests/winDde.test
@@ -24,7 +24,7 @@ if {[testConstraint win]} {
 	testConstraint dde 1
     }
 }
-testConstraint notWine [expr {$::tcl_platform(platform) ne "windows" || ![info exists ::env(TRAVIS_OS_NAME)] || ![string match linux $::env(TRAVIS_OS_NAME)]}]
+testConstraint notWine [expr {![info exists ::env(CI_USING_WINE)]}]
 
 
 # -------------------------------------------------------------------------
diff --git a/tests/winFCmd.test b/tests/winFCmd.test
index 70db379..1fb3e5f 100644
--- a/tests/winFCmd.test
+++ b/tests/winFCmd.test
@@ -28,8 +28,10 @@ testConstraint testchmod      [llength [info commands testchmod]]
 testConstraint cdrom 0
 testConstraint exdev 0
 testConstraint longFileNames 0
-testConstraint knownMsvcBug [expr {![info exists ::env(TRAVIS_OS_NAME)] || ![string match windows $::env(TRAVIS_OS_NAME)]}]
-testConstraint notWine [expr {$::tcl_platform(platform) ne "windows" || ![info exists ::env(TRAVIS_OS_NAME)] || ![string match linux $::env(TRAVIS_OS_NAME)]}]
+# Some things fail under all Continuous Integration systems for subtle reasons
+# such as CI often running with elevated privileges in a container.
+testConstraint notInCIenv     [expr {![info exists ::env(CI)]}]
+testConstraint knownMsvcBug   [expr {![info exists ::env(CI_BUILD_WITH_MSVC)]}]
 
 proc createfile {file {string a}} {
     set f [open $file w]
@@ -133,25 +135,25 @@ test winFCmd-1.1 {TclpRenameFile: errno: EACCES} -body {
 } -constraints {win cdrom testfile} -returnCodes error -result EACCES
 test winFCmd-1.2 {TclpRenameFile: errno: EEXIST} -setup {
     cleanup
-} -constraints {win testfile notWine} -body {
+} -constraints {win testfile notInCIenv} -body {
     file mkdir td1/td2/td3
     file mkdir td2
     testfile mv td2 td1/td2
 } -returnCodes error -result EEXIST
 test winFCmd-1.3 {TclpRenameFile: errno: EINVAL} -setup {
     cleanup
-} -constraints {win testfile notWine} -body {
+} -constraints {win testfile notInCIenv} -body {
     testfile mv / td1
 } -returnCodes error -result EINVAL
 test winFCmd-1.4 {TclpRenameFile: errno: EINVAL} -setup {
     cleanup
-} -constraints {win testfile notWine} -body {
+} -constraints {win testfile notInCIenv} -body {
     file mkdir td1
     testfile mv td1 td1/td2
 } -returnCodes error -result EINVAL
 test winFCmd-1.5 {TclpRenameFile: errno: EISDIR} -setup {
     cleanup
-} -constraints {win testfile notWine} -body {
+} -constraints {win testfile notInCIenv} -body {
     file mkdir td1
     createfile tf1
     testfile mv tf1 td1
@@ -256,7 +258,7 @@ test winFCmd-1.22 {TclpRenameFile: long dst} -setup {
 } -returnCodes error -result ENAMETOOLONG
 test winFCmd-1.23 {TclpRenameFile: move dir into self} -setup {
     cleanup
-} -constraints {win testfile notWine} -body {
+} -constraints {win testfile notInCIenv} -body {
     file mkdir td1
     testfile mv [pwd]/td1 td1/td2
 } -returnCodes error -result EINVAL
@@ -301,21 +303,21 @@ test winFCmd-1.29 {TclpRenameFile: src is dir} -setup {
 } -returnCodes error -result ENOTDIR
 test winFCmd-1.30 {TclpRenameFile: dst is dir} -setup {
     cleanup
-} -constraints {win testfile notWine} -body {
+} -constraints {win testfile notInCIenv} -body {
     file mkdir td1
     file mkdir td2/td2
     testfile mv td1 td2
 } -returnCodes error -result EEXIST
 test winFCmd-1.31 {TclpRenameFile: TclpRemoveDirectory fails} -setup {
     cleanup
-} -constraints {win testfile notWine} -body {
+} -constraints {win testfile notInCIenv} -body {
     file mkdir td1
     file mkdir td2/td2
     testfile mv td1 td2
 } -returnCodes error -result EEXIST
 test winFCmd-1.32 {TclpRenameFile: TclpRemoveDirectory succeeds} -setup {
     cleanup
-} -constraints {win testfile notWine} -body {
+} -constraints {win testfile notInCIenv} -body {
     file mkdir td1/td2
     file mkdir td2
     testfile mv td1 td2
@@ -344,7 +346,7 @@ test winFCmd-1.34 {TclpRenameFile: src is dir, dst is not} -setup {
 } -returnCodes error -result ENOTDIR
 test winFCmd-1.35 {TclpRenameFile: src is not dir, dst is} -setup {
     cleanup
-} -constraints {win testfile notWine} -body {
+} -constraints {win testfile notInCIenv} -body {
     file mkdir td1
     createfile tf1
     testfile mv tf1 td1
@@ -395,7 +397,7 @@ proc MakeFiles {dirname} {
 
 test winFCmd-1.38 {TclpRenameFile: check rename of conflicting inodes} -setup {
     cleanup
-} -constraints {win winNonZeroInodes knownMsvcBug notWine} -body {
+} -constraints {win winNonZeroInodes knownMsvcBug notInCIenv} -body {
     file mkdir td1
     foreach {a b} [MakeFiles td1] break
     file rename -force $a $b
@@ -640,7 +642,7 @@ test winFCmd-5.1 {TclpCopyDirectory: calls TraverseWinTree} -setup {
 
 test winFCmd-6.1 {TclpRemoveDirectory: errno: EACCES} -setup {
     cleanup
-} -constraints {winVista testfile testchmod knownMsvcBug notWine} -body {
+} -constraints {winVista testfile testchmod knownMsvcBug notInCIenv} -body {
     file mkdir td1
     testchmod 0 td1
     testfile rmdir td1
@@ -694,7 +696,7 @@ test winFCmd-6.8 {TclpRemoveDirectory: RemoveDirectory fails} -setup {
 } -result {1 {tf1 ENOTDIR}}
 test winFCmd-6.9 {TclpRemoveDirectory: errno == EACCES} -setup {
     cleanup
-} -constraints {winVista testfile testchmod knownMsvcBug notWine} -body {
+} -constraints {winVista testfile testchmod knownMsvcBug notInCIenv} -body {
     file mkdir td1
     testchmod 0 td1
     testfile rmdir td1
@@ -705,14 +707,14 @@ test winFCmd-6.9 {TclpRemoveDirectory: errno == EACCES} -setup {
 } -result {td1 EACCES}
 test winFCmd-6.11 {TclpRemoveDirectory: attr == -1} -setup {
     cleanup
-} -constraints {win testfile notWine} -body {
+} -constraints {win testfile notInCIenv} -body {
     testfile rmdir /
     # WinXP returns EEXIST, WinNT seems to return EACCES.  No policy
     # decision has been made as to which is correct.
 } -returnCodes error -match regexp -result {^/ E(ACCES|EXIST)$}
 test winFCmd-6.13 {TclpRemoveDirectory: write-protected} -setup {
     cleanup
-} -constraints {winVista testfile testchmod knownMsvcBug notWine} -body {
+} -constraints {winVista testfile testchmod knownMsvcBug notInCIenv} -body {
     file mkdir td1
     testchmod 0 td1
     testfile rmdir td1
@@ -941,7 +943,7 @@ test winFCmd-9.1 {TraversalDelete: DOTREE_F} -setup {
 } -result {}
 test winFCmd-9.3 {TraversalDelete: DOTREE_PRED} -setup {
     cleanup
-} -constraints {winVista testfile testchmod knownMsvcBug notWine} -body {
+} -constraints {winVista testfile testchmod knownMsvcBug notInCIenv} -body {
     file mkdir td1/td2
     testchmod 0 td1
     testfile rmdir -force td1
@@ -1130,7 +1132,7 @@ test winFCmd-15.2 {SetWinFileAttributes - archive} -constraints {win} -setup {
 } -cleanup {
     cleanup
 } -result {{} 1}
-test winFCmd-15.3 {SetWinFileAttributes - archive} -constraints {win notWine} -setup {
+test winFCmd-15.3 {SetWinFileAttributes - archive} -constraints {win notInCIenv} -setup {
     cleanup
 } -body {
     createfile td1 {}
@@ -1138,7 +1140,7 @@ test winFCmd-15.3 {SetWinFileAttributes - archive} -constraints {win notWine} -s
 } -cleanup {
     cleanup
 } -result {{} 0}
-test winFCmd-15.4 {SetWinFileAttributes - hidden} -constraints {win notWine} -setup {
+test winFCmd-15.4 {SetWinFileAttributes - hidden} -constraints {win notInCIenv} -setup {
     cleanup
 } -body {
     createfile td1 {}
@@ -1171,7 +1173,7 @@ test winFCmd-15.7 {SetWinFileAttributes - readonly} -setup {
 } -cleanup {
     cleanup
 } -result {{} 0}
-test winFCmd-15.8 {SetWinFileAttributes - system} -constraints {win notWine} -setup {
+test winFCmd-15.8 {SetWinFileAttributes - system} -constraints {win notInCIenv} -setup {
     cleanup
 } -body {
     createfile td1 {}
diff --git a/tests/winFile.test b/tests/winFile.test
index 2c0988a..5e0731f 100644
--- a/tests/winFile.test
+++ b/tests/winFile.test
@@ -24,7 +24,7 @@ testConstraint notNTFS 0
 if {[testConstraint testvolumetype]} {
     testConstraint notNTFS [expr {[testvolumetype] eq "NTFS"}]
 }
-testConstraint notWine [expr {$::tcl_platform(platform) ne "windows" || ![info exists ::env(TRAVIS_OS_NAME)] || ![string match linux $::env(TRAVIS_OS_NAME)]}]
+testConstraint notWine [expr {![info exists ::env(CI_USING_WINE)]}]
 
 test winFile-1.1 {TclpGetUserHome} -constraints {win} -body {
     glob ~nosuchuser
diff --git a/tests/winPipe.test b/tests/winPipe.test
index 919e336..8656f0a 100644
--- a/tests/winPipe.test
+++ b/tests/winPipe.test
@@ -28,7 +28,7 @@ set org_pwd [pwd]
 set bindir [file join $org_pwd [file dirname [info nameofexecutable]]]
 set cat32 [file join $bindir cat32.exe]
 
-testConstraint notWine [expr {$::tcl_platform(platform) ne "windows" || ![info exists ::env(TRAVIS_OS_NAME)] || ![string match linux $::env(TRAVIS_OS_NAME)]}]
+testConstraint notWine [expr {![info exists ::env(CI_USING_WINE)]}]
 
 
 # several test-cases here expect current directory == [temporaryDirectory]:
diff --git a/tests/winTime.test b/tests/winTime.test
index 19e4c58..68be966 100644
--- a/tests/winTime.test
+++ b/tests/winTime.test
@@ -19,7 +19,9 @@ if {"::tcltest" ni [namespace children]} {
 catch [list package require -exact Tcltest [info patchlevel]]
 
 testConstraint testwinclock [llength [info commands testwinclock]]
-testConstraint knownMsvcBug [expr {![info exists ::env(TRAVIS_OS_NAME)] || ![string match windows $::env(TRAVIS_OS_NAME)]}]
+# Some things fail under all Continuous Integration systems for subtle reasons
+# such as CI often running with elevated privileges in a container.
+testConstraint notInCIenv   [expr {![info exists ::env(CI)]}]
 
 # The next two tests will crash on Windows if the check for negative
 # clock values is not done properly.
@@ -41,7 +43,7 @@ test winTime-1.2 {TclpGetDate} {win} {
 # with the Windows clock.  30 sec really isn't enough,
 # but how much time does a tester have patience for?
 
-test winTime-2.1 {Synchronization of Tcl and Windows clocks} {testwinclock knownMsvcBug} {
+test winTime-2.1 {Synchronization of Tcl and Windows clocks} {testwinclock notInCIenv} {
     # May fail due to OS/hardware discrepancies.  See:
     # http://support.microsoft.com/default.aspx?scid=kb;en-us;274323
     set failed {}