OpProgress: Erase lines when done

It's interesting to the user to see the progress when it happens,
but arguably once it's done it is just visual clutter, so let's
not write newlines, and when we are done, instead of appending
"Done", let's just empty the line.

This requires some effort to keep apt-cdrom happy which just writes
lines to stdout itself. Bad apt-cdrom. Maybe there is a better fix
for it, but this gets us going.

3 files changed, 12 insertions, 4 deletions

diff --git a/apt-pkg/contrib/progress.cc b/apt-pkg/contrib/progress.cc
index a2c4332ca..df068e43a 100644
--- a/apt-pkg/contrib/progress.cc
+++ b/apt-pkg/contrib/progress.cc
@@ -153,13 +153,15 @@ void OpTextProgress::Done()
 {
    if (NoUpdate == false && OldOp.empty() == false)
    {
-      char S[300];
+      char S[300] = {};
       if (_error->PendingError() == true)
 	 snprintf(S,sizeof(S),_("%c%s... Error!"),'\r',OldOp.c_str());
-      else
+      else if (not _config->FindB("APT::Internal::OpProgress::EraseLines", true))
 	 snprintf(S,sizeof(S),_("%c%s... Done"),'\r',OldOp.c_str());
       Write(S);
-      cout << endl;
+      // FIXME: apt-cdrom relies on this end of line being printed
+      if (_error->PendingError() || not _config->FindB("APT::Internal::OpProgress::EraseLines", true))
+         cout << endl;
       OldOp = string();
    }
 
@@ -200,7 +202,8 @@ void OpTextProgress::Update()
    {
       snprintf(S,sizeof(S),"\r%s",OldOp.c_str());
       Write(S);
-      cout << endl;
+      if (_config->FindB("APT::Internal::OpProgress::EraseLines", true))
+         cout << endl;
    }
 
    // Print the spinner. Absolute progress shows us a time progress.
diff --git a/apt-private/private-cmndline.cc b/apt-private/private-cmndline.cc
index cbab22031..505f1f2b8 100644
--- a/apt-private/private-cmndline.cc
+++ b/apt-private/private-cmndline.cc
@@ -481,6 +481,10 @@ static bool ShowCommonHelp(APT_CMD const Binary, CommandLine &CmdL, std::vector<
 static void BinarySpecificConfiguration(char const * const Binary)	/*{{{*/
 {
    std::string const binary = flNotDir(Binary);
+   if (binary == "apt-cdrom" || binary == "apt-config")
+   {
+      _config->CndSet("Binary::apt-cdrom::APT::Internal::OpProgress::EraseLines", false);
+   }
    if (binary == "apt" || binary == "apt-config")
    {
       if (getenv("NO_COLOR") == nullptr)
diff --git a/doc/examples/configure-index b/doc/examples/configure-index
index 9a2bcbf1c..a8fc98daa 100644
--- a/doc/examples/configure-index
+++ b/doc/examples/configure-index
@@ -881,6 +881,7 @@ Rred::f "<BOOL>";
 Rred::Compress "<STRING>";
 
 APT::Internal::OpProgress::Absolute "<BOOL>";
+APT::Internal::OpProgress::EraseLines "<BOOL>";
 APT::Color "<BOOL>";
 
 update-manager::always-include-phased-updates "<BOOL>";