docs: preserve the modification date when copying the prebuilt man page

The previously built man page "curl.1" must be copied with the original
modification date, otherwise the man page is never updated.

This fixes a bug that has been introduced with commit 2568441cab.

Reviewed-by: Dan Fandrich
Reviewed-by: Daniel Stenberg
Closes #12199

diff --git a/docs/Makefile.am b/docs/Makefile.am
index 5454e8330373fd468b5312042dbdbaf1a78d784f..9190b441136bc0cabde1adc3ba9210c968f28413 100644 (file)
--- a/docs/Makefile.am
+++ b/docs/Makefile.am
@@ -111,7 +111,8 @@ SUFFIXES = .1 .html .pdf
 # have changed.
 $(abs_builddir)/curl.1:
        if test "$(top_builddir)x" != "$(top_srcdir)x" -a -e "$(srcdir)/curl.1"; then \
-               $(INSTALL_DATA) "$(srcdir)/curl.1" $@; fi
+               $(INSTALL_DATA) "$(srcdir)/curl.1" $@ \
+               && touch -r "$(srcdir)/curl.1" $@; fi
        cd cmdline-opts && $(MAKE)
 
 html: $(HTMLPAGES)