sqv, gpgv: Do not fail if Dir::Etc::Trusted is set and trusted.gpg.d is missing

This should remain a warning case for now. So push the errors
to a stack and see if we can find any file.

Explictly warn again if Dir::Etc::trusted is set, as it is like
_super_ deprecated.

Reported-By: Cyril Brulebois <kibi@debian.org> in Bug#1032131

3 files changed, 69 insertions, 2 deletions

diff --git a/apt-pkg/contrib/gpgv.cc b/apt-pkg/contrib/gpgv.cc
index 173bfdf22..c6eabc690 100644
--- a/apt-pkg/contrib/gpgv.cc
+++ b/apt-pkg/contrib/gpgv.cc
@@ -395,12 +395,20 @@ void ExecGPGV(std::string const &File, std::string const &FileGPG,
       }
    }
 
-   std::vector<std::string> Parts;
    if (not FoundKeyring)
    {
-      Parts = GetListOfFilesInDir(_config->FindDir("Dir::Etc::TrustedParts"), std::vector<std::string>{"gpg", "asc"}, true);
+      // Either trusted or trustedparts must exist
+      _error->PushToStack();
+      auto Parts = GetListOfFilesInDir(_config->FindDir("Dir::Etc::TrustedParts"), std::vector<std::string>{"gpg", "asc"}, true);
       if (auto trusted = _config->FindFile("Dir::Etc::Trusted"); not trusted.empty())
+      {
+	 apt_warning(std::cerr, statusfd, fd, "Loading %s from deprecated option Dir::Etc::Trusted\n", trusted.c_str());
 	 Parts.push_back(trusted);
+      }
+      if (Parts.empty())
+	 _error->MergeWithStack();
+      else
+	 _error->RevertToStack();
       for (auto &Part : Parts)
       {
 	 if (Debug)
diff --git a/methods/sqv.cc b/methods/sqv.cc
index 9dbe75994..3191752cc 100644
--- a/methods/sqv.cc
+++ b/methods/sqv.cc
@@ -132,9 +132,20 @@ bool SQVMethod::VerifyGetSigners(const char *file, const char *outfile,
    };
    if (keyFiles.empty())
    {
+      // Either trusted or trustedparts must exist
+      _error->PushToStack();
       auto Parts = GetListOfFilesInDir(_config->FindDir("Dir::Etc::TrustedParts"), std::vector<std::string>{"gpg", "asc"}, true);
       if (auto trusted = _config->FindFile("Dir::Etc::Trusted"); not trusted.empty())
+      {
+	 std::string s;
+	 strprintf(s, "Loading %s from deprecated option Dir::Etc::Trusted\n", trusted.c_str());
+	 Warning(std::move(s));
 	 Parts.push_back(trusted);
+      }
+      if (Parts.empty())
+	 _error->MergeWithStack();
+      else
+	 _error->RevertToStack();
       for (auto &Part : Parts)
       {
 	 if (Debug)
diff --git a/test/integration/test-method-gpgv-legacy-keyring b/test/integration/test-method-gpgv-legacy-keyring
new file mode 100755
index 000000000..55ad2463d
--- /dev/null
+++ b/test/integration/test-method-gpgv-legacy-keyring
@@ -0,0 +1,48 @@
+#!/bin/sh
+set -e
+
+TESTDIR="$(readlink -f "$(dirname "$0")")"
+. "$TESTDIR/framework"
+
+setupenvironment
+configarchitecture "amd64"
+
+insertpackage 'testing' 'foo' 'all' '1'
+
+buildaptarchive
+setupaptarchive --no-update
+changetowebserver
+
+alias inrelease_size="stat -c %s aptarchive/dists/testing/InRelease"
+
+testsuccessequal "Get:1 http://localhost:${APTHTTPPORT} testing InRelease [$(inrelease_size) B]
+Get:2 http://localhost:${APTHTTPPORT} testing/main all Packages [248 B]
+Get:3 http://localhost:${APTHTTPPORT} testing/main Translation-en [225 B]
+Reading package lists..." aptget update -q
+
+mv rootdir/etc/apt/trusted.gpg.d/joesixpack.gpg rootdir/etc/apt/trusted.gpg
+
+if test -e "${METHODSDIR}/sqv"; then
+    missing_key="The signatures couldn't be verified because no keyring is specified"
+else
+    missing_key="The following signatures couldn't be verified because the public key is not available: NO_PUBKEY 5A90D141DBAC8DAE"
+fi
+
+testwarningequal "Hit:1 http://localhost:${APTHTTPPORT} testing InRelease
+Reading package lists...
+W: http://localhost:${APTHTTPPORT}/dists/testing/InRelease: Loading ${TMPWORKINGDIRECTORY}/rootdir/etc/apt/trusted.gpg from deprecated option Dir::Etc::Trusted" aptget update -q -o Dir::Etc::trusted=trusted.gpg
+
+testwarningequal "Hit:1 http://localhost:${APTHTTPPORT} testing InRelease
+Err:1 http://localhost:${APTHTTPPORT} testing InRelease
+  $missing_key
+Reading package lists...
+W: An error occurred during the signature verification. The repository is not updated and the previous index files will be used. GPG error: http://localhost:${APTHTTPPORT} testing InRelease: $missing_key
+W: Failed to fetch http://localhost:${APTHTTPPORT}/dists/testing/InRelease  $missing_key
+W: Some index files failed to download. They have been ignored, or old ones used instead." aptget update -q
+
+rmdir rootdir/etc/apt/trusted.gpg.d
+
+testwarningequal "Hit:1 http://localhost:${APTHTTPPORT} testing InRelease
+Reading package lists...
+W: http://localhost:${APTHTTPPORT}/dists/testing/InRelease: Loading ${TMPWORKINGDIRECTORY}/rootdir/etc/apt/trusted.gpg from deprecated option Dir::Etc::Trusted" aptget update -q -o Dir::Etc::trusted=trusted.gpg
+