Run CMake.HTML test without net access (#10857)

Use xmllint's --nonet option to avoid downloading the xhtml DTD.
Provide the DTD and its dependencies locally.

1 files changed, 9 insertions, 1 deletions

diff --git a/Utilities/CMakeLists.txt b/Utilities/CMakeLists.txt
index ecae7b0c9c..4aa87196ad 100644
--- a/Utilities/CMakeLists.txt
+++ b/Utilities/CMakeLists.txt
@@ -138,8 +138,16 @@ if(BUILD_TESTING)
   endif()
   mark_as_advanced(LIBXML2_XMLLINT_EXECUTABLE)
   if(LIBXML2_XMLLINT_EXECUTABLE)
+    # We provide the XHTML DTD and its dependencies in the 'xml'
+    # directory so that xmllint can run without network access.
+    # However, it's --path option accepts a space-separated list of
+    # paths so it cannot handle spaces in the path to the source tree.
+    # Therefore we run the tool with the current work directory set to
+    # the 'xml' directory and use '.' as the path.
     add_test(CMake.HTML
-      ${LIBXML2_XMLLINT_EXECUTABLE} --valid --noout ${HTML_FILES}
+      ${CMAKE_CMAKE_COMMAND} -E chdir ${CMAKE_CURRENT_SOURCE_DIR}/xml
+      ${LIBXML2_XMLLINT_EXECUTABLE} --valid --noout --nonet --path .
+      ${HTML_FILES}
       )
   endif()
 endif()