12 files changed, 9 insertions, 143 deletions
diff --git a/docutils/COPYING.txt b/docutils/COPYING.txt
index 5fef895b9..a1894072c 100644
--- a/docutils/COPYING.txt
+++ b/docutils/COPYING.txt
@@ -70,12 +70,6 @@ Exceptions
 
 The exceptions to the `Public Domain Dedication`_ above are:
 
-* docutils/writers/s5_html/themes/default/iepngfix.htc:
-
-      IE5.5+ PNG Alpha Fix v1.0 by Angus Turnbull
-      <http://www.twinhelix.com>.  Free usage permitted as long as
-      this notice remains intact.
-
 * docutils/utils/math/__init__.py,
   docutils/utils/math/latex2mathml.py,
   docutils/writers/xetex/__init__.py,
diff --git a/docutils/HISTORY.txt b/docutils/HISTORY.txt
index 24b120381..eb0886951 100644
--- a/docutils/HISTORY.txt
+++ b/docutils/HISTORY.txt
@@ -36,6 +36,11 @@ Changes Since 0.17.1
 
   - Fix option "detailled" under Python 2.7.
 
+* docutils/writers/s5_html/themes/default
+
+  - Remove IE 6 compatibility workarounds ``iepngfix.htc`` and
+    ``blank.gif`` (fixes bug #169).
+
 Release 0.17.1 (2021-04-16)
 ===========================
 
diff --git a/docutils/RELEASE-NOTES.txt b/docutils/RELEASE-NOTES.txt
index 4c4c31aa7..f819b957f 100644
--- a/docutils/RELEASE-NOTES.txt
+++ b/docutils/RELEASE-NOTES.txt
@@ -38,9 +38,6 @@ Future changes
 
 * `htm4css1` writer: Support the embed_images_ option.
 
-* `s5_html` writer: Remove the IE PNG Fix by Angus Turnbull. IE has
-  native PNG support since version 7.
-
 * Make <meta> a standard Docutils doctree node.
 
   The `meta directive`__ will insert <meta> instead of pending nodes.
@@ -101,6 +98,8 @@ Release 0.18.dev
 
 * Config setting `legacy_class_functions`_: default changed to "False".
   
+* `s5_html` writer: Removed ``iepngfix.htc`` (workaround for IE 6).
+  
 
 Release 0.17.1 (2021-04-16)
 ===========================
diff --git a/docutils/docs/user/slide-shows.txt b/docutils/docs/user/slide-shows.txt
index 579942113..aa7c1e130 100644
--- a/docutils/docs/user/slide-shows.txt
+++ b/docutils/docs/user/slide-shows.txt
@@ -645,12 +645,6 @@ stylesheets, JavaScript, and graphics:
      code also manages the fallback to Opera Show if you're using
      the Opera web browser.
 
-     Two files are included to support PNG transparency (alpha
-     channels) in Internet Explorer:
-
-     - iepngfix.htc
-     - blank.gif
-
 
 Making a Custom Theme
 =====================
diff --git a/docutils/docutils/writers/s5_html/__init__.py b/docutils/docutils/writers/s5_html/__init__.py
index fbc5d2ff5..4eaa32ec4 100644
--- a/docutils/docutils/writers/s5_html/__init__.py
+++ b/docutils/docutils/writers/s5_html/__init__.py
@@ -143,7 +143,7 @@ class S5HTMLTranslator(html4css1.HTMLTranslator):
     """Names of theme files directly linked to in the output HTML"""
 
     indirect_theme_files = (
-        's5-core.css', 'framing.css', 'pretty.css', 'blank.gif', 'iepngfix.htc')
+        's5-core.css', 'framing.css', 'pretty.css')
     """Names of files used indirectly; imported or used by files in
     `direct_theme_files`."""
 
diff --git a/docutils/docutils/writers/s5_html/themes/README.txt b/docutils/docutils/writers/s5_html/themes/README.txt
index 2e01b51ee..605d08f5d 100644
--- a/docutils/docutils/writers/s5_html/themes/README.txt
+++ b/docutils/docutils/writers/s5_html/themes/README.txt
@@ -1,4 +1,4 @@
-Except where otherwise noted (default/iepngfix.htc), all files in this
+Except where otherwise noted, all files in this
 directory have been released into the Public Domain.
 
 These files are based on files from S5 1.1, released into the Public
diff --git a/docutils/docutils/writers/s5_html/themes/default/blank.gif b/docutils/docutils/writers/s5_html/themes/default/blank.gif
deleted file mode 100644
index 75b945d25..000000000
--- a/docutils/docutils/writers/s5_html/themes/default/blank.gif
+++ /dev/null
diff --git a/docutils/docutils/writers/s5_html/themes/default/iepngfix.htc b/docutils/docutils/writers/s5_html/themes/default/iepngfix.htc
deleted file mode 100644
index 9f3d628b5..000000000
--- a/docutils/docutils/writers/s5_html/themes/default/iepngfix.htc
+++ /dev/null
@@ -1,42 +0,0 @@
-<public:component>
-<public:attach event="onpropertychange" onevent="doFix()" />
-
-<script>
-
-// IE5.5+ PNG Alpha Fix v1.0 by Angus Turnbull http://www.twinhelix.com
-// Free usage permitted as long as this notice remains intact.
-
-// This must be a path to a blank image. That's all the configuration you need here.
-var blankImg = 'ui/default/blank.gif';
-
-var f = 'DXImageTransform.Microsoft.AlphaImageLoader';
-
-function filt(s, m) {
- if (filters[f]) {
-  filters[f].enabled = s ? true : false;
-  if (s) with (filters[f]) { src = s; sizingMethod = m }
- } else if (s) style.filter = 'progid:'+f+'(src="'+s+'",sizingMethod="'+m+'")';
-}
-
-function doFix() {
- if ((parseFloat(navigator.userAgent.match(/MSIE (\S+)/)[1]) < 5.5) ||
-  (event && !/(background|src)/.test(event.propertyName))) return;
-
- if (tagName == 'IMG') {
-  if ((/\.png$/i).test(src)) {
-   filt(src, 'image');  // was 'scale'
-   src = blankImg;
-  } else if (src.indexOf(blankImg) < 0) filt();
- } else if (style.backgroundImage) {
-  if (style.backgroundImage.match(/^url[("']+(.*\.png)[)"']+$/i)) {
-   var s = RegExp.$1;
-   style.backgroundImage = '';
-   filt(s, 'crop');
-  } else filt();
- }
-}
-
-doFix();
-
-</script>
-</public:component>
-\ No newline at end of file
diff --git a/docutils/test/functional/expected/ui/default/blank.gif b/docutils/test/functional/expected/ui/default/blank.gif
deleted file mode 100644
index 75b945d25..000000000
--- a/docutils/test/functional/expected/ui/default/blank.gif
+++ /dev/null
diff --git a/docutils/test/functional/expected/ui/default/iepngfix.htc b/docutils/test/functional/expected/ui/default/iepngfix.htc
deleted file mode 100644
index 9f3d628b5..000000000
--- a/docutils/test/functional/expected/ui/default/iepngfix.htc
+++ /dev/null
@@ -1,42 +0,0 @@
-<public:component>
-<public:attach event="onpropertychange" onevent="doFix()" />
-
-<script>
-
-// IE5.5+ PNG Alpha Fix v1.0 by Angus Turnbull http://www.twinhelix.com
-// Free usage permitted as long as this notice remains intact.
-
-// This must be a path to a blank image. That's all the configuration you need here.
-var blankImg = 'ui/default/blank.gif';
-
-var f = 'DXImageTransform.Microsoft.AlphaImageLoader';
-
-function filt(s, m) {
- if (filters[f]) {
-  filters[f].enabled = s ? true : false;
-  if (s) with (filters[f]) { src = s; sizingMethod = m }
- } else if (s) style.filter = 'progid:'+f+'(src="'+s+'",sizingMethod="'+m+'")';
-}
-
-function doFix() {
- if ((parseFloat(navigator.userAgent.match(/MSIE (\S+)/)[1]) < 5.5) ||
-  (event && !/(background|src)/.test(event.propertyName))) return;
-
- if (tagName == 'IMG') {
-  if ((/\.png$/i).test(src)) {
-   filt(src, 'image');  // was 'scale'
-   src = blankImg;
-  } else if (src.indexOf(blankImg) < 0) filt();
- } else if (style.backgroundImage) {
-  if (style.backgroundImage.match(/^url[("']+(.*\.png)[)"']+$/i)) {
-   var s = RegExp.$1;
-   style.backgroundImage = '';
-   filt(s, 'crop');
-  } else filt();
- }
-}
-
-doFix();
-
-</script>
-</public:component>
-\ No newline at end of file
diff --git a/docutils/test/functional/expected/ui/small-black/blank.gif b/docutils/test/functional/expected/ui/small-black/blank.gif
deleted file mode 100644
index 75b945d25..000000000
--- a/docutils/test/functional/expected/ui/small-black/blank.gif
+++ /dev/null
diff --git a/docutils/test/functional/expected/ui/small-black/iepngfix.htc b/docutils/test/functional/expected/ui/small-black/iepngfix.htc
deleted file mode 100644
index fa9f99659..000000000
--- a/docutils/test/functional/expected/ui/small-black/iepngfix.htc
+++ /dev/null
@@ -1,42 +0,0 @@
-<public:component>
-<public:attach event="onpropertychange" onevent="doFix()" />
-
-<script>
-
-// IE5.5+ PNG Alpha Fix v1.0 by Angus Turnbull http://www.twinhelix.com
-// Free usage permitted as long as this notice remains intact.
-
-// This must be a path to a blank image. That's all the configuration you need here.
-var blankImg = 'ui/small-black/blank.gif';
-
-var f = 'DXImageTransform.Microsoft.AlphaImageLoader';
-
-function filt(s, m) {
- if (filters[f]) {
-  filters[f].enabled = s ? true : false;
-  if (s) with (filters[f]) { src = s; sizingMethod = m }
- } else if (s) style.filter = 'progid:'+f+'(src="'+s+'",sizingMethod="'+m+'")';
-}
-
-function doFix() {
- if ((parseFloat(navigator.userAgent.match(/MSIE (\S+)/)[1]) < 5.5) ||
-  (event && !/(background|src)/.test(event.propertyName))) return;
-
- if (tagName == 'IMG') {
-  if ((/\.png$/i).test(src)) {
-   filt(src, 'image');  // was 'scale'
-   src = blankImg;
-  } else if (src.indexOf(blankImg) < 0) filt();
- } else if (style.backgroundImage) {
-  if (style.backgroundImage.match(/^url[("']+(.*\.png)[)"']+$/i)) {
-   var s = RegExp.$1;
-   style.backgroundImage = '';
-   filt(s, 'crop');
-  } else filt();
- }
-}
-
-doFix();
-
-</script>
-</public:component>
-\ No newline at end of file