${force} now overwrites existing files in fetch_http()

The wget program will not overwrite a file unless -O is used to specify the
output file name on the command line.  This patch enables -O
${local_snapshots}/${getfile} to overwrite the existing file if ${force} is
specified.

It also moves a check for ${force} to the top of the function
so that fetch_http() won't return 0 automatically if ${force} is specified
but the ${getfile} already exists.  This also allows us to squash an
if-block around the wget call.

A test-case was added to verify that fetch_http works with ${force} = yes.

Change-Id: I685011b3383bd0aa7f1cf01a31ca22b77c0c5d41

2 files changed, 40 insertions, 23 deletions

diff --git a/lib/fetch.sh b/lib/fetch.sh
index c7ef74db..f9ac0fea 100755
--- a/lib/fetch.sh
+++ b/lib/fetch.sh
@@ -135,7 +135,9 @@ fetch_http()
 	fi
     fi
 
-    if test -e ${local_snapshots}/${getfile}; then
+    # If it exists and the caller didn't ask for downloading to be forced then
+    # we don't need to download it again.
+    if test -e ${local_snapshots}/${getfile} -a x"${force}" != xyes; then
 	notice "${getfile} already exists."
 	return 0
     elif test x"${supdate}" = xno; then
@@ -150,29 +152,26 @@ fetch_http()
 	return 1
     fi
 
-    if test ! -e ${local_snapshots}/${getfile} -o x"${force}" = xyes; then
-	# We don't want this message for md5sums, since it's so often
-	# downloaded.
-	if test x"${getfile}" != x"md5sums"; then
-	    notice "Downloading ${getfile} to ${local_snapshots}"
-	fi
+    # We don't want this message for md5sums, since it's so often
+    # downloaded.
+    if test x"${getfile}" != x"md5sums"; then
+        notice "Downloading ${getfile} to ${local_snapshots}"
+    fi
 
-	# NOTE: the timeout is short, and we only try twice to access the
-	# remote host. This is to improve performance when offline, or
-	# the remote host is offline.
-	dryrun "${wget_bin} ${wget_quiet:+-q} --timeout=${wget_timeout}${wget_progress_style:+ --progress=${wget_progress_style}} --tries=2 --directory-prefix=${local_snapshots}/${dir} http://${fileserver}/${remote_snapshots}/${getfile}"
-	ret=$?
-	if test x"${dryrun}" != xyes -a ! -s ${local_snapshots}/${getfile}; then
-	    warning "downloaded file ${getfile} has zero data!"
-	    return 1
-	fi
-    else
-	# We don't want this message for md5sums, since it's so often
-	# downloaded.
-	if test x"${getfile}" != x"md5sums"; then
-	    notice "${getfile} already exists in ${local_snapshots}"
-	fi
+    local overwrite=
+    if test x${force} = xyes; then
+	overwrite="-O ${local_snapshots}/${getfile}"
     fi
+
+    # NOTE: the timeout is short, and we only try twice to access the
+    # remote host. This is to improve performance when offline, or
+    # the remote host is offline.
+    dryrun "${wget_bin} ${wget_quiet:+-q} --timeout=${wget_timeout}${wget_progress_style:+ --progress=${wget_progress_style}} --tries=2 --directory-prefix=${local_snapshots}/${dir} http://${fileserver}/${remote_snapshots}/${getfile}${overwrite:+ ${overwrite}}"
+    if test x"${dryrun}" != xyes -a ! -s ${local_snapshots}/${getfile}; then
+       warning "downloaded file ${getfile} has zero data!"
+       return 1
+    fi
+
     return 0
 }
 
diff --git a/testsuite/test.sh b/testsuite/test.sh
index a3c47bf4..3417ff21 100755
--- a/testsuite/test.sh
+++ b/testsuite/test.sh
@@ -555,7 +555,8 @@ sleep 1s
 out="`supdate=yes fetch_http infrastructure/gmp-5.1.3.tar.xz 2>/dev/null`"
 ret=$?
 
-# Compare the second timestamp to make sure they're equal.
+# Compare the second timestamp to make sure they're equal (i.e., that a new
+# one wasn't downloaded).
 gmp_stamp2=`stat -c %X ${local_snapshots}/infrastructure/gmp-5.1.3.tar.xz`
 
 if test $ret -eq 0 -a ${gmp_stamp1} -eq ${gmp_stamp2}; then
@@ -564,6 +565,23 @@ else
     fail "fetch_http infrastructure/gmp-5.1.3.tar.xz with \${supdate}=yes"
 fi
 
+# Sleep so that the timestamps differ (if they will)
+sleep 1s
+
+# Try to download it again with supdate=yes and force=yes explicit it
+# should download it again and return 0 (and the timestamp should differ)
+out="`force=yes supdate=yes fetch_http infrastructure/gmp-5.1.3.tar.xz 2>/dev/null`"
+ret=$?
+
+# Compare to the second timestamp to make sure they're not equal.
+gmp_stamp3=`stat -c %X ${local_snapshots}/infrastructure/gmp-5.1.3.tar.xz`
+
+if test $ret -eq 0 -a ${gmp_stamp2} -ne ${gmp_stamp3}; then
+    pass "fetch_http infrastructure/gmp-5.1.3.tar.xz with \${supdate}=yes and \${force}=yes"
+else
+    fail "fetch_http infrastructure/gmp-5.1.3.tar.xz with \${supdate}=yes and \${force}=yes"
+fi
+
 out="`fetch_http md5sums 2>/dev/null`"
 if test $? -eq 0; then
     pass "fetch_http md5sums"