New: --trust-server-names saves Metalink/HTTP xml files using the "name" field

* src/metalink.c (retrieve_from_metalink): If opt.trustservernames is
  true, use the basename of the metaurl's name to save the xml file
* doc/metalink-standard.txt: Update doc. With --trust-server-names any
  Metalink/HTTP Link application/metalink4+xml file is saved using the
  basename of the "name" field, if any. Update Metalink/HTTP examples
* testenv/Makefile.am: Add new file
* testenv/Test-metalink-http-xml-trust-name.py: New file. Metalink/HTTP
  automated Metalink/XML, save xml files using the "name" field tests

doc/metalink-standard.txt

@@ -83,6 +83,9 @@ When --trust-server-names is on, the metalink:file "name" field parsed
 from Metalink/XML files is trusted. When no Metalink/XML is available,
 the mother URL is trusted.
 
+Any Metalink/HTTP application/metalink4+xml file is saved using the
+basename of its own Link header "name" field, if available.
+
 3.1.2 The final name
 ====================
 
@@ -183,6 +186,13 @@ type="application/pgp-signature"
 Digest: SHA-256=MWVkMWQxYTRiMzk5MDQ0MzI3NGU5NDEyZTk5OWY1ZGFmNzgyZTJlO
 DYzYjRjYzFhOTlmNTQwYzI2M2QwM2U2MQ==
 
+See [2 #section-4].
+
+Link: <http://example.com/example.ext.torrent>; rel=describedby;
+type="application/x-bittorrent"; name="differentname.ext"
+Link: <http://example.com/example.ext.meta4>; rel=describedby;
+type="application/metalink4+xml"
+
 5.4 Saving files
 ================
 

src/metalink.c

@@ -241,7 +241,7 @@ retrieve_from_metalink (const metalink_t* metalink)
                 metafile = xstrdup (safename);
 
                 if (opt.trustservernames)
-                  replace_metalink_basename (&metafile, murl->url);
+                  replace_metalink_basename (&metafile, murl->name ? murl->name : murl->url);
                 else
                   append_suffix_number (&metafile, ".meta#", meta_count);
 

testenv/Makefile.am

@@ -32,6 +32,7 @@ if METALINK_IS_ENABLED
     Test-metalink-http-baddigest.py                 \
     Test-metalink-http-xml.py                       \
     Test-metalink-http-xml-trust.py                 \
+    Test-metalink-http-xml-trust-name.py            \
     Test-metalink-xml.py                            \
     Test-metalink-xml-continue.py                   \
     Test-metalink-xml-relpath.py                    \

testenv/Test-metalink-http-xml-trust-name.py

@@ -0,0 +1,272 @@
+#!/usr/bin/env python3
+from sys import exit
+from test.http_test import HTTPTest
+from misc.wget_file import WgetFile
+import hashlib
+from base64 import b64encode
+
+"""
+    This is to test Metalink/HTTP with Metalink/XML Link headers.
+
+    With --trust-server-names, trust the metalink:file names.
+
+    Without --trust-server-names, don't trust the metalink:file names:
+    use the basename of --input-metalink, and add a sequential number
+    (e.g. .#1, .#2, etc.).
+
+    Strip the directory from unsafe paths.
+"""
+
+############# File Definitions ###############################################
+bad = "Ouch!"
+bad_sha256 = hashlib.sha256 (bad.encode ('UTF-8')).hexdigest ()
+
+File1 = "Would you like some Tea?"
+File1_lowPref = "Do not take this"
+File1_sha256 = hashlib.sha256 (File1.encode ('UTF-8')).hexdigest ()
+
+File2 = "This is gonna be good"
+File2_lowPref = "Not this one too"
+File2_sha256 = hashlib.sha256 (File2.encode ('UTF-8')).hexdigest ()
+
+File3 = "A little more, please"
+File3_lowPref = "That's just too much"
+File3_sha256 = hashlib.sha256 (File3.encode ('UTF-8')).hexdigest ()
+
+File4 = "Maybe a biscuit?"
+File4_lowPref = "No, thanks"
+File4_sha256 = hashlib.sha256 (File4.encode ('UTF-8')).hexdigest ()
+
+File5 = "More Tea...?"
+File5_lowPref = "I have to go..."
+File5_sha256 = hashlib.sha256 (File5.encode ('UTF-8')).hexdigest ()
+
+MetaXml1 = \
+"""<?xml version="1.0" encoding="utf-8"?>
+<metalink version="3.0" xmlns="http://www.metalinker.org/">
+  <publisher>
+    <name>GNU Wget</name>
+  </publisher>
+  <license>
+    <name>GNU GPL</name>
+    <url>http://www.gnu.org/licenses/gpl.html</url>
+  </license>
+  <identity>Wget Test Files</identity>
+  <version>1.2.3</version>
+  <description>Wget Test Files description</description>
+  <files>
+    <file name="dir/File1">
+      <verification>
+        <hash type="sha256">{{FILE1_HASH}}</hash>
+      </verification>
+      <resources>
+        <url type="http" preference="35">http://{{SRV_HOST}}:{{SRV_PORT}}/wrong_file</url>
+        <url type="http" preference="40">http://{{SRV_HOST}}:{{SRV_PORT}}/404</url>
+        <url type="http" preference="25">http://{{SRV_HOST}}:{{SRV_PORT}}/File1_lowPref</url>
+        <url type="http" preference="30">http://{{SRV_HOST}}:{{SRV_PORT}}/File1</url>
+      </resources>
+    </file>
+    <file name="dir/File2">
+      <verification>
+        <hash type="sha256">{{FILE2_HASH}}</hash>
+      </verification>
+      <resources>
+        <url type="http" preference="35">http://{{SRV_HOST}}:{{SRV_PORT}}/wrong_file</url>
+        <url type="http" preference="40">http://{{SRV_HOST}}:{{SRV_PORT}}/404</url>
+        <url type="http" preference="25">http://{{SRV_HOST}}:{{SRV_PORT}}/File2_lowPref</url>
+        <url type="http" preference="30">http://{{SRV_HOST}}:{{SRV_PORT}}/File2</url>
+      </resources>
+    </file>
+    <file name="/dir/File3"> <!-- rejected by libmetalink -->
+      <verification>
+        <hash type="sha256">{{FILE3_HASH}}</hash>
+      </verification>
+      <resources>
+        <url type="http" preference="35">http://{{SRV_HOST}}:{{SRV_PORT}}/wrong_file</url>
+        <url type="http" preference="40">http://{{SRV_HOST}}:{{SRV_PORT}}/404</url>
+        <url type="http" preference="25">http://{{SRV_HOST}}:{{SRV_PORT}}/File3_lowPref</url>
+        <url type="http" preference="30">http://{{SRV_HOST}}:{{SRV_PORT}}/File3</url>
+      </resources>
+    </file>
+    <file name="dir/File4">
+      <verification>
+        <hash type="sha256">{{FILE4_HASH}}</hash>
+      </verification>
+      <resources>
+        <url type="http" preference="35">http://{{SRV_HOST}}:{{SRV_PORT}}/wrong_file</url>
+        <url type="http" preference="40">http://{{SRV_HOST}}:{{SRV_PORT}}/404</url>
+        <url type="http" preference="25">http://{{SRV_HOST}}:{{SRV_PORT}}/File4_lowPref</url>
+        <url type="http" preference="30">http://{{SRV_HOST}}:{{SRV_PORT}}/File4</url>
+      </resources>
+    </file>
+    <file name="dir/File5">
+      <verification>
+        <hash type="sha256">{{FILE5_HASH}}</hash>
+      </verification>
+      <resources>
+        <url type="http" preference="35">http://{{SRV_HOST}}:{{SRV_PORT}}/wrong_file</url>
+        <url type="http" preference="40">http://{{SRV_HOST}}:{{SRV_PORT}}/404</url>
+        <url type="http" preference="25">http://{{SRV_HOST}}:{{SRV_PORT}}/File5_lowPref</url>
+        <url type="http" preference="30">http://{{SRV_HOST}}:{{SRV_PORT}}/File5</url>
+      </resources>
+    </file>
+  </files>
+</metalink>
+"""
+
+MetaXml2 = \
+"""<?xml version="1.0" encoding="utf-8"?>
+<metalink version="3.0" xmlns="http://www.metalinker.org/">
+  <publisher>
+    <name>GNU Wget</name>
+  </publisher>
+  <license>
+    <name>GNU GPL</name>
+    <url>http://www.gnu.org/licenses/gpl.html</url>
+  </license>
+  <identity>Wget Test Files</identity>
+  <version>1.2.3</version>
+  <description>Wget Test Files description</description>
+  <files>
+    <file name="bad">
+      <verification>
+        <hash type="sha256">{{BAD_HASH}}</hash>
+      </verification>
+      <resources>
+        <url type="http" preference="35">http://{{SRV_HOST}}:{{SRV_PORT}}/wrong_file</url>
+        <url type="http" preference="40">http://{{SRV_HOST}}:{{SRV_PORT}}/404</url>
+        <url type="http" preference="30">http://{{SRV_HOST}}:{{SRV_PORT}}/bad</url>
+      </resources>
+    </file>
+  </files>
+</metalink>
+"""
+
+LinkHeaders = [
+    # This file has the lowest priority, and should go last
+    "<http://{{SRV_HOST}}:{{SRV_PORT}}/test1.metalink>; rel=describedby; pri=2; type=\"application/metalink4+xml\"; name=\"newname.metalink\"",
+    # This file has the highest priority, and should go first
+    "<http://{{SRV_HOST}}:{{SRV_PORT}}/test2.metalink>; rel=describedby; pri=1; type=\"application/metalink4+xml\""
+]
+
+# This will be filled as soon as we know server hostname and port
+MetaHTTPRules = {'SendHeader' : {}}
+
+MetaHTTP = WgetFile ("main.metalink", rules=MetaHTTPRules)
+
+wrong_file = WgetFile ("wrong_file", bad)
+
+File1_orig = WgetFile ("File1", File1)
+File1_down = WgetFile ("dir/File1", File1)
+File1_nono = WgetFile ("File1_lowPref", File1_lowPref)
+
+File2_orig = WgetFile ("File2", File2)
+File2_down = WgetFile ("dir/File2", File2)
+File2_nono = WgetFile ("File2_lowPref", File2_lowPref)
+
+# rejected by libmetalink
+File3_orig = WgetFile ("File3", File3)
+File3_nono = WgetFile ("File3_lowPref", File3_lowPref)
+
+File4_orig = WgetFile ("File4", File4)
+File4_down = WgetFile ("dir/File4", File4)
+File4_nono = WgetFile ("File4_lowPref", File4_lowPref)
+
+File5_orig = WgetFile ("File5", File5)
+File5_down = WgetFile ("dir/File5", File5)
+File5_nono = WgetFile ("File5_lowPref", File5_lowPref)
+
+MetaFile1 = WgetFile ("test1.metalink", MetaXml1)
+MetaFile1_down = WgetFile ("newname.metalink", MetaXml1)
+
+MetaFile2 = WgetFile ("test2.metalink", MetaXml2)
+
+WGET_OPTIONS = "--trust-server-names --metalink-over-http --metalink-index=2"
+WGET_URLS = [["main.metalink"]]
+
+RequestList = [[
+    "HEAD /main.metalink",
+    "GET /404",
+    "GET /wrong_file",
+    "GET /test1.metalink",
+    "GET /File1",
+    "GET /File2",
+    "GET /File4",
+    "GET /File5"
+]]
+
+Files = [[
+    MetaHTTP,
+    wrong_file,
+    MetaFile1, MetaFile2,
+    File1_orig, File1_nono,
+    File2_orig, File2_nono,
+    File3_orig, File3_nono,
+    File4_orig, File4_nono,
+    File5_orig, File5_nono
+]]
+Existing_Files = []
+
+ExpectedReturnCode = 0
+ExpectedDownloadedFiles = [
+    MetaFile1_down,
+    File1_down,
+    File2_down,
+    File4_down,
+    File5_down
+]
+
+################ Pre and Post Test Hooks #####################################
+pre_test = {
+    "ServerFiles"       : Files,
+    "LocalFiles"        : Existing_Files
+}
+test_options = {
+    "WgetCommands"      : WGET_OPTIONS,
+    "Urls"              : WGET_URLS
+}
+post_test = {
+    "ExpectedFiles"     : ExpectedDownloadedFiles,
+    "ExpectedRetcode"   : ExpectedReturnCode,
+    "FilesCrawled"      : RequestList
+}
+
+http_test = HTTPTest (
+                pre_hook=pre_test,
+                test_params=test_options,
+                post_hook=post_test
+)
+
+http_test.server_setup()
+### Get and use dynamic server sockname
+srv_host, srv_port = http_test.servers[0].server_inst.socket.getsockname ()
+
+MetaXml1 = MetaXml1.replace('{{FILE1_HASH}}', File1_sha256)
+MetaXml1 = MetaXml1.replace('{{FILE2_HASH}}', File2_sha256)
+MetaXml1 = MetaXml1.replace('{{FILE3_HASH}}', File3_sha256)
+MetaXml1 = MetaXml1.replace('{{FILE4_HASH}}', File4_sha256)
+MetaXml1 = MetaXml1.replace('{{FILE5_HASH}}', File5_sha256)
+MetaXml1 = MetaXml1.replace('{{SRV_HOST}}', srv_host)
+MetaXml1 = MetaXml1.replace('{{SRV_PORT}}', str (srv_port))
+MetaFile1.content = MetaXml1
+MetaFile1_down.content = MetaXml1
+
+MetaXml2 = MetaXml2.replace('{{BAD_HASH}}', bad_sha256)
+MetaXml2 = MetaXml2.replace('{{SRV_HOST}}', srv_host)
+MetaXml2 = MetaXml2.replace('{{SRV_PORT}}', str (srv_port))
+MetaFile2.content = MetaXml2
+
+# Helper function for hostname, port and digest substitution
+def SubstituteServerInfo (text, host, port):
+    text = text.replace('{{SRV_HOST}}', host)
+    text = text.replace('{{SRV_PORT}}', str (port))
+    return text
+
+MetaHTTPRules["SendHeader"] = {
+        'Link': [ SubstituteServerInfo (LinkHeader, srv_host, srv_port)
+                    for LinkHeader in LinkHeaders ]
+}
+
+err = http_test.begin ()
+
+exit (err)