From e5bb443cf58cec23503ad0deeeb06a080053da8a Mon Sep 17 00:00:00 2001
From: David Kalnischkies <david@kalnischkies.de>
Date: Sat, 7 Nov 2020 22:52:20 +0100
Subject: Support compressed output from rred similar to apt-helper cat-file

---
 apt-private/private-cmndline.cc   |  1 +
 doc/examples/configure-index      |  1 +
 methods/rred.cc                   | 36 ++++++++++++++++++++++++++++++++++--
 test/integration/test-method-rred | 15 +++++++++++++--
 4 files changed, 49 insertions(+), 4 deletions(-)

diff --git a/apt-private/private-cmndline.cc b/apt-private/private-cmndline.cc
index b6c5ca90a..588dea06b 100644
--- a/apt-private/private-cmndline.cc
+++ b/apt-private/private-cmndline.cc
@@ -366,6 +366,7 @@ static bool addArgumentsRred(std::vector<CommandLine::Args> &Args, char const *
 {
    addArg('t', nullptr, "Rred::T", 0);
    addArg('f', nullptr, "Rred::F", 0);
+   addArg('C', "compress", "Rred::Compress",CommandLine::HasArg);
    return true;
 }
 									/*}}}*/
diff --git a/doc/examples/configure-index b/doc/examples/configure-index
index ee031c8b4..0af923811 100644
--- a/doc/examples/configure-index
+++ b/doc/examples/configure-index
@@ -832,6 +832,7 @@ dir::dpkg::triplettable "<FILE>";
 dir::dpkg::cputable "<FILE>";
 Rred::t "<BOOL>";
 Rred::f "<BOOL>";
+Rred::Compress "<STRING>";
 
 APT::Internal::OpProgress::Absolute "<BOOL>";
 APT::Color "<BOOL>";
diff --git a/methods/rred.cc b/methods/rred.cc
index 0184456bf..2164cd19e 100644
--- a/methods/rred.cc
+++ b/methods/rred.cc
@@ -756,6 +756,19 @@ class RredMethod : public aptMethod {
    }
 };
 
+static const APT::Configuration::Compressor *FindCompressor(std::vector<APT::Configuration::Compressor> const &compressors, std::string const &name) /*{{{*/
+{
+   APT::Configuration::Compressor const * compressor = nullptr;
+   for (auto const & c : compressors)
+   {
+      if (compressor != nullptr && c.Cost >= compressor->Cost)
+         continue;
+      if (c.Name == name || c.Extension == name || (!c.Extension.empty() && c.Extension.substr(1) == name))
+         compressor = &c;
+   }
+   return compressor;
+}
+									/*}}}*/
 static std::vector<aptDispatchWithHelp> GetCommands()
 {
    return {{nullptr, nullptr, nullptr}};
@@ -773,6 +786,19 @@ int main(int argc, const char *argv[])
    auto const argmax = CmdL.FileSize();
    bool const quiet = _config->FindI("quiet", 0) >= 2;
 
+   std::string const compressorName = _config->Find("Rred::Compress", "");
+   auto const compressors = APT::Configuration::getCompressors();
+   APT::Configuration::Compressor const * compressor = nullptr;
+   if (not compressorName.empty())
+   {
+      compressor = FindCompressor(compressors, compressorName);
+      if (compressor == nullptr)
+      {
+	 std::cerr << "E: Could not find compressor: " << compressorName << '\n';
+	 return 101;
+      }
+   }
+
    bool just_diff = false;
    if (_config->FindB("Rred::T", false))
    {
@@ -784,12 +810,18 @@ int main(int argc, const char *argv[])
       if (not quiet)
 	 std::clog << "Patching " << CmdL.FileList[0] << " into " << CmdL.FileList[1] << "\n";
       input.Open(CmdL.FileList[0], FileFd::ReadOnly,FileFd::Extension);
-      output.Open(CmdL.FileList[1], FileFd::WriteOnly | FileFd::Create | FileFd::Empty | FileFd::BufferedWrite, FileFd::Extension);
+      if (compressor == nullptr)
+	 output.Open(CmdL.FileList[1], FileFd::WriteOnly | FileFd::Create | FileFd::Empty | FileFd::BufferedWrite, FileFd::Extension);
+      else
+	 output.Open(CmdL.FileList[1], FileFd::WriteOnly | FileFd::Create | FileFd::Empty | FileFd::BufferedWrite, *compressor);
       argi = 2;
    }
    else
    {
-      output.OpenDescriptor(STDOUT_FILENO, FileFd::WriteOnly | FileFd::Create | FileFd::BufferedWrite);
+      if (compressor == nullptr)
+	 output.OpenDescriptor(STDOUT_FILENO, FileFd::WriteOnly | FileFd::Create | FileFd::BufferedWrite);
+      else
+	 output.OpenDescriptor(STDOUT_FILENO, FileFd::WriteOnly | FileFd::Create | FileFd::BufferedWrite, *compressor);
       if (_config->FindB("Rred::F", false))
 	 input.OpenDescriptor(STDIN_FILENO, FileFd::ReadOnly);
       else
diff --git a/test/integration/test-method-rred b/test/integration/test-method-rred
index bef1a35e0..fcadac146 100755
--- a/test/integration/test-method-rred
+++ b/test/integration/test-method-rred
@@ -198,9 +198,13 @@ failrred 'End before start' '7,6d'
 
 # deal correctly with patch merging
 mergepatches() {
-	testsuccess runapt "${METHODSDIR}/rred" Packages.ed-*
+	local CONTENT="$1"
+	shift
+	testsuccess runapt "${METHODSDIR}/rred" Packages.ed-* "$@"
 	cp -a rootdir/tmp/testsuccess.output patch.ed
-	testfileequal 'patch.ed' "$1"
+	if [ "$#" = '0' ]; then
+		testfileequal 'patch.ed' "$CONTENT"
+	fi
 }
 createpatch() {
 	echo "$2"
@@ -223,7 +227,14 @@ mergepatches '11,19c
 Package: extra-kittens
 Version: unavailable
 .
+6d' -C 'gzip'
+mv patch.ed patch.ed.gz
+mergepatches '11,19c
+Package: extra-kittens
+Version: unavailable
+.
 6d'
+testfileequal patch.ed "$(apt-helper cat-file patch.ed.gz)"
 testrred 'Apply' 'merged patch' "$(cat patch.ed)" 'Package: coolstuff
 Version: 0.8.15
 Description: collection of stuff
-- 
cgit v1.2.3-18-g5258