[PATCH libnetfilter_queue 1/2] build: doc: Only fix rendering of verbatim '\n"' when needed

[Duncan Roe <duncan_roe@xxxxxxxxxxxxxxx>]

commit 9f52afa60839 ("build: doc: Fix rendering of verbatim '\n"' in man
pages") worked around a doxygen bug which was fixed at doxygen 1.9.
Applying the workaround to output from a fixed doxygen version reintroduced
the bug.
Update build_man.sh to record doxygen version and only apply workaround
if that version is broken.

Fixes: 9f52afa60839 ("build: doc: Fix rendering of verbatim '\n"' in man pages")
Signed-off-by: Duncan Roe <duncan_roe@xxxxxxxxxxxxxxx>
---
 doxygen/build_man.sh | 9 ++++++++-
 1 file changed, 8 insertions(+), 1 deletion(-)

diff --git a/doxygen/build_man.sh b/doxygen/build_man.sh
index 95c7569..a6531cb 100755
--- a/doxygen/build_man.sh
+++ b/doxygen/build_man.sh
@@ -68,6 +68,13 @@ post_process(){
   #
   #keep_me=nfq_icmp_get_hdr.3
   #do_diagnostics
+
+  # Decide if we need to fix rendering of verbatim "\n"
+  i=$(doxygen --version)
+  doxymajor=$(echo $i|cut -f1 -d.)
+  doxyminor=$(echo $i|cut -f2 -d.)
+  [ $doxymajor -eq 1 -a $doxyminor -lt 9 ] &&
+    fix_newlines=true || fix_newlines=false
   #
   # Work through the "real" man pages
   for target in $(ls -S | head -n$page_count)
@@ -84,7 +91,7 @@ post_process(){
       [ $# -ne 2 ] || insert_see_also $@
 
       # Fix rendering of verbatim "\n" (in code snippets)
-      sed -i 's/\\n/\\\\n/' $target
+      $fix_newlines && sed -i 's/\\n/\\\\n/' $target
     }&
 
   done
-- 
2.46.2