[libvirt] [PATCH v2 3/7] m4: readline: Comment rl_completion_quote_character() check
The check was added in 74416b1d4849 without offering any
explanation outside of the commit message. Introduce a comment
to make digging through the git history unnecessary.
Signed-off-by: Andrea Bolognani <abologna(a)redhat.com>
---
m4/virt-readline.m4 | 6 ++++++
1 file changed, 6 insertions(+)
diff --git a/m4/virt-readline.m4 b/m4/virt-readline.m4
index 4823a27788..649a52edfa 100644
--- a/m4/virt-readline.m4
+++ b/m4/virt-readline.m4
@@ -37,6 +37,12 @@ AC_DEFUN([LIBVIRT_CHECK_READLINE],[
LIBS="$lv_saved_libs $extra_LIBS"
fi
+ # This function is present in all reasonable (5.0+) readline versions;
+ # however, the macOS base system contains a library called libedit which
+ # takes over the readline name despite lacking many of its features. We
+ # want to make sure we only enable readline support when linking against
+ # the actual readline library, and the availability of this specific
+ # functions is as good a witness for that fact as any.
AC_CHECK_DECLS([rl_completion_quote_character],
[], [],
[[#include <stdio.h>
--
2.20.1