[PATCH] gendocs.sh: don't overwrite existing index.html

[Sergey Poznyakoff]

When generating html output, texi2html 5.0 creates index.html
file, instead of $PORJECT.html.  Don't overwrite it with dangling
symlink.
---
 build-aux/gendocs.sh | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/build-aux/gendocs.sh b/build-aux/gendocs.sh
index 1872de9..0828905 100755
--- a/build-aux/gendocs.sh
+++ b/build-aux/gendocs.sh
@@ -2,7 +2,7 @@
 # gendocs.sh -- generate a GNU manual in many formats.  This script is
 #   mentioned in maintain.texi.  See the help message below for usage details.
 
-scriptversion=2021-01-01.00
+scriptversion=2021-03-01.13
 
 # Copyright 2003-2021 Free Software Foundation, Inc.
 #
@@ -346,7 +346,9 @@ html_split()
   split_html_dir=$PACKAGE.html
   (
     cd ${split_html_dir} || exit 1
-    ln -sf ${PACKAGE}.html index.html
+    if [ ! -f index.html ]; then
+       ln -sf ${PACKAGE}.html index.html
+    fi
     tar -czf "$abs_outdir/${PACKAGE}.html_$1.tar.gz" -- *.html
   )
   eval html_$1_tgz_size=`calcsize "$outdir/${PACKAGE}.html_$1.tar.gz"`
-- 
2.9.0