Introduce inrelease-path option for sources.list

Allow specifying an alternative path to the InRelease file, so
you can have multiple versions of a repository, for example.

Enabling this option disables fallback to Release and Release.gpg,
so setting it to InRelease can be used to ensure that only that
will be tried.

We add two test cases: One for checking that it works, and another
for checking that the fallback does not happen.

Closes: #886745

1 files changed, 21 insertions, 4 deletions

diff --git a/apt-pkg/acquire-item.cc b/apt-pkg/acquire-item.cc
index 611876dd2..7fcc5867a 100644
--- a/apt-pkg/acquire-item.cc
+++ b/apt-pkg/acquire-item.cc
@@ -1324,9 +1324,13 @@ bool pkgAcqMetaBase::CheckDownloadDone(pkgAcqTransactionItem * const I, const st
    // Save the final base URI we got this Release file from
    if (I->UsedMirror.empty() == false && _config->FindB("Acquire::SameMirrorForAllIndexes", true))
    {
-      if (APT::String::Endswith(I->Desc.URI, "InRelease"))
+      auto InReleasePath = Target.Option(IndexTarget::INRELEASE_PATH);
+      if (InReleasePath.empty())
+	 InReleasePath = "InRelease";
+
+      if (APT::String::Endswith(I->Desc.URI, InReleasePath))
       {
-	 TransactionManager->BaseURI = I->Desc.URI.substr(0, I->Desc.URI.length() - strlen("InRelease"));
+	 TransactionManager->BaseURI = I->Desc.URI.substr(0, I->Desc.URI.length() - InReleasePath.length());
 	 TransactionManager->UsedMirror = I->UsedMirror;
       }
       else if (APT::String::Endswith(I->Desc.URI, "Release"))
@@ -1871,6 +1875,7 @@ void pkgAcqMetaClearSig::Failed(string const &Message,pkgAcquire::MethodConfig c
       auto const failreason = LookupTag(Message, "FailReason");
       auto const httperror = "HttpError";
       if (Status == StatAuthError ||
+	  Target.Option(IndexTarget::INRELEASE_PATH).empty() == false || /* do not fallback if InRelease was requested */
 	  (strncmp(failreason.c_str(), httperror, strlen(httperror)) == 0 &&
 	   failreason != "HttpError404"))
       {
@@ -1880,7 +1885,7 @@ void pkgAcqMetaClearSig::Failed(string const &Message,pkgAcquire::MethodConfig c
 	 // as this is gonna fail anyway and instead abort our try (LP#346386)
 	 _error->PushToStack();
 	 _error->Error(_("Failed to fetch %s  %s"), Target.URI.c_str(), ErrorText.c_str());
-	 if (AllowInsecureRepositories(InsecureType::UNSIGNED, Target.Description, TransactionManager->MetaIndexParser, TransactionManager, this) == true)
+	 if (Target.Option(IndexTarget::INRELEASE_PATH).empty() == true && AllowInsecureRepositories(InsecureType::UNSIGNED, Target.Description, TransactionManager->MetaIndexParser, TransactionManager, this) == true)
 	    _error->RevertToStack();
 	 else
 	    return;
@@ -1941,7 +1946,19 @@ pkgAcqMetaIndex::pkgAcqMetaIndex(pkgAcquire * const Owner,		/*{{{*/
    Desc.Description = DataTarget.Description;
    Desc.Owner = this;
    Desc.ShortDesc = DataTarget.ShortDesc;
-   Desc.URI = DataTarget.URI;
+
+   // Rewrite the description URI if INRELEASE_PATH was specified so
+   // we download the specified file instead.
+   auto InReleasePath = DataTarget.Option(IndexTarget::INRELEASE_PATH);
+   if (InReleasePath.empty() == false && APT::String::Endswith(DataTarget.URI, "/InRelease"))
+   {
+      Desc.URI = DataTarget.URI.substr(0, DataTarget.URI.size() - strlen("InRelease")) + InReleasePath;
+   }
+   else
+   {
+      Desc.URI = DataTarget.URI;
+   }
+
    QueueURI(Desc);
 }
 									/*}}}*/