cmdline-docs/Makefile: avoid using a fixed temp file name

By appending the pid number two different runs at the same time will not
trample over the same file.

Reported-by: Jon Rumsey
Fixes #12829
Closes #12839

diff --git a/docs/cmdline-opts/Makefile.am b/docs/cmdline-opts/Makefile.am
index e9b35ac05269d32eeb652afc24fe202340e661be..08d19a015228d8af5db3812b598c79f09e2be70b 100644 (file)
--- a/docs/cmdline-opts/Makefile.am
+++ b/docs/cmdline-opts/Makefile.am
@@ -38,7 +38,7 @@ GN_ = $(GN_0)
 all: $(MANPAGE)
 
 $(MANPAGE): $(DPAGES) $(SUPPORT) mainpage.idx Makefile.inc gen.pl
-       $(GEN)(rm -f $(MANPAGE) && cd $(srcdir) && @PERL@ ./gen.pl mainpage $(DPAGES) > $(builddir)/manpage.tmp && mv $(builddir)/manpage.tmp $(MANPAGE))
+       $(GEN)(rm -f $(MANPAGE) && cd $(srcdir) && @PERL@ ./gen.pl mainpage $(DPAGES) > $(builddir)/manpage.tmp.$$$$ && mv $(builddir)/manpage.tmp.$$$$ $(MANPAGE))
 
 listhelp:
        ./gen.pl listhelp $(DPAGES) > $(top_builddir)/src/tool_listhelp.c