1 files changed, 22 insertions, 0 deletions

diff --git a/doc/Makefile.am b/doc/Makefile.am
index eb23b534b..5f8c2b6d0 100644
--- a/doc/Makefile.am
+++ b/doc/Makefile.am
@@ -1,4 +1,26 @@
 # This Makefile.am is in the public domain
+
+if ACTIVATE_TEXINFO4
+# NOTE: While GNU makeinfo 6.5 supports --css-ref=URL,
+# makeinfo 4.8 (in NetBSD 8.0, macOS, and maybe other
+# base) does only support --css-include=FILE.
+# The only difference is a shorter html output and
+# in 6.5 the ability to use refs instead of include.
+# We prefer not to break builds in this case, so
+# we use the include version which is backwards compatible
+# and upwards compatible, while the ref variant is neither.
+AM_MAKEINFOHTMLFLAGS = --no-split --css-include=style.css --css-include=manual.css
+else
+# In the 5.x version they added `--split=chapters|sections` in
+# addition to `--split=nodes`.
+# Hold on to your hats: In version 6.5 this is already removed, ffs.
+# GNU Texinfo, please be more consistent than 1 version in switches.
+# This however is compatible to version 5.2. Thanks, I hate it.
+# AM_MAKEINFOHTMLFLAGS = --split=sections --css-ref="../style.css" --css-ref="../manual.css"
+AM_MAKEINFOHTMLFLAGS = --split --css-ref="../style.css" --css-ref="../manual.css"
+endif
+
+
 if DOCUMENTATION
   SUBDIRS = doxygen handbook tutorial
 endif