Add --disable-check-autofiles to configure

ChangeLog

@@ -2,6 +2,12 @@
 
 	* 8.3.0: release
 
+	* Add configure flag --enable-check-autofiles, which is on by
+	default. Packagers whose packaging systems automatically refresh
+	autoconf or libtool files should pass --disable-check-autofiles to
+	./configure to suppress warnings about automatically generated
+	files being outdated.
+
 2019-01-06  Jay Berkenbilt  <ejb@ql.org>
 
 	* Remove the restriction in most cases that the source QPDF used

autofiles.sums

@@ -1,4 +1,4 @@
-17b7466a112e85278a43dee35f0aa61aa093476b8886929634db9f2b6b298f19  configure.ac
+b544741ebe32e6bf555703b4cbedcaef62553da29e3230df4ccb8351900e2378  configure.ac
 35bc5c645dc42d47f2daeea06f8f3e767c8a1aee6a35eb2b4854fd2ce66c3413  m4/ax_random_device.m4
 37f8897d5f68d7d484e5457832a8f190ddb7507fa2a467cb7ee2be40a4364643  m4/libtool.m4
 e77ebba8361b36f14b4d0927173a034b98c5d05049697a9ded84d85eb99a7990  m4/ltoptions.m4

configure

@@ -744,6 +744,7 @@ SHELL'
 ac_subst_files=''
 ac_user_opts='
 enable_option_checking
+enable_check_autofiles
 enable_shared
 enable_static
 with_pic
@@ -1409,6 +1410,10 @@ Optional Features:
   --disable-option-checking  ignore unrecognized --enable/--with options
   --disable-FEATURE       do not include FEATURE (same as --enable-FEATURE=no)
   --enable-FEATURE[=ARG]  include FEATURE [ARG=yes]
+  --enable-check-autofiles
+                          if specified, verify checksums on automatically
+                          generated files (default=yes); package maintainers
+                          may want to disable this
   --enable-shared[=PKGS]  build shared libraries [default=yes]
   --enable-static[=PKGS]  build static libraries [default=yes]
   --enable-fast-install[=PKGS]
@@ -2448,6 +2453,18 @@ ac_config_files="$ac_config_files libqpdf.map"
 ac_config_headers="$ac_config_headers libqpdf/qpdf/qpdf-config.h"
 
 
+# Check whether --enable-check-autofiles was given.
+if test "${enable_check_autofiles+set}" = set; then :
+  enableval=$enable_check_autofiles; if test "$enableval" = "no"; then
+      CHECK_AUTOFILES=0
+    else
+      CHECK_AUTOFILES=1
+    fi
+else
+  CHECK_AUTOFILES=1
+fi
+
+
 # Check to see if automatically generated files are outdated and if we
 # can update them.
 # Extract the first word of "autoconf", so it can be a program name with args.
@@ -2602,7 +2619,7 @@ $as_echo "no" >&6; }
 fi
 
 
-if test "$AUTOCONF$AUTOHEADER$ACLOCAL$SHA256SUM" = "1111"; then
+if test "$CHECK_AUTOFILES$AUTOCONF$AUTOHEADER$ACLOCAL$SHA256SUM" = "11111"; then
    if ! sha256sum -c autofiles.sums; then
        as_fn_error $? "autofiles are autodated; rerun autogen.sh" "$LINENO" 5
    fi

configure.ac

@@ -11,13 +11,23 @@ AC_CONFIG_FILES([libqpdf.pc])
 AC_CONFIG_FILES([libqpdf.map])
 AC_CONFIG_HEADERS([libqpdf/qpdf/qpdf-config.h])
 
+AC_ARG_ENABLE(check-autofiles,
+   AS_HELP_STRING([--enable-check-autofiles],
+		  [if specified, verify checksums on automatically generated files (default=yes); package maintainers may want to disable this]),
+   [if test "$enableval" = "no"; then
+      CHECK_AUTOFILES=0
+    else
+      CHECK_AUTOFILES=1
+    fi],
+   [CHECK_AUTOFILES=1])
+
 # Check to see if automatically generated files are outdated and if we
 # can update them.
 AC_CHECK_PROG(AUTOCONF,autoconf,1,0)
 AC_CHECK_PROG(AUTOHEADER,autoheader,1,0)
 AC_CHECK_PROG(ACLOCAL,aclocal,1,0)
 AC_CHECK_PROG(SHA256SUM,sha256sum,1,0)
-if test "$AUTOCONF$AUTOHEADER$ACLOCAL$SHA256SUM" = "1111"; then
+if test "$CHECK_AUTOFILES$AUTOCONF$AUTOHEADER$ACLOCAL$SHA256SUM" = "11111"; then
    if ! sha256sum -c autofiles.sums; then
        AC_MSG_ERROR(autofiles are autodated; rerun autogen.sh)
    fi