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authorJulian Andres Klode <julian.klode@canonical.com>2018-12-18 14:50:25 +0100
committerJulian Andres Klode <julian.klode@canonical.com>2019-02-01 17:51:35 +0100
commit8bb2a91a070170d7d8e71206d1c66a26809bdbc3 (patch)
tree049c96e291e2e2c11f09d984a7af91c60caa061a /apt-pkg/policy.cc
parent4200469bb5a14c4659285917ed30c46a0b15c286 (diff)
Introduce experimental 'never' pinning for sources
This allows disabling a repository by pinning it to 'never', which is internally translated to a value of -32768 (or whatever the minimum of short is). This overrides any other pin for that repository. It can be used to make sure certain sources are never used; for example, in unattended-upgrades. To prevent semantic changes to existing files, we substitute min + 1 for every pin-priority: <min>. This is a temporary solution, as we are waiting for an ABI break. To add pins with that value, the special Pin-Priority "never" may be used for now. It's unclear if that will persist, or if the interface will change eventually.
Diffstat (limited to 'apt-pkg/policy.cc')
-rw-r--r--apt-pkg/policy.cc23
1 files changed, 20 insertions, 3 deletions
diff --git a/apt-pkg/policy.cc b/apt-pkg/policy.cc
index d7eb43c0f..6de439d32 100644
--- a/apt-pkg/policy.cc
+++ b/apt-pkg/policy.cc
@@ -38,6 +38,8 @@
using namespace std;
+constexpr short NEVER_PIN = std::numeric_limits<short>::min();
+
// Policy::Init - Startup and bind to a cache /*{{{*/
// ---------------------------------------------------------------------
/* Set the defaults for operation. The default mode with no loaded policy
@@ -107,7 +109,7 @@ bool pkgPolicy::InitDefaults()
pkgVersionMatch Match(I->Data,I->Type);
for (pkgCache::PkgFileIterator F = Cache->FileBegin(); F != Cache->FileEnd(); ++F)
{
- if (Fixed[F->ID] == false && Match.FileMatch(F) == true)
+ if ((Fixed[F->ID] == false || I->Priority == NEVER_PIN) && PFPriority[F->ID] != NEVER_PIN && Match.FileMatch(F) == true)
{
PFPriority[F->ID] = I->Priority;
@@ -271,7 +273,14 @@ APT_PURE signed short pkgPolicy::GetPriority(pkgCache::PkgIterator const &Pkg)
APT_PURE signed short pkgPolicy::GetPriority(pkgCache::VerIterator const &Ver, bool ConsiderFiles)
{
if (VerPins[Ver->ID].Type != pkgVersionMatch::None)
- return VerPins[Ver->ID].Priority;
+ {
+ // If all sources are never pins, the never pin wins.
+ if (VerPins[Ver->ID].Priority == NEVER_PIN)
+ return NEVER_PIN;
+ for (pkgCache::VerFileIterator file = Ver.FileList(); file.end() == false; file++)
+ if (GetPriority(file.File()) != NEVER_PIN)
+ return VerPins[Ver->ID].Priority;
+ }
if (!ConsiderFiles)
return 0;
@@ -388,9 +397,17 @@ bool ReadPinFile(pkgPolicy &Plcy,string File)
for (; Word != End && isspace(*Word) != 0; Word++);
_error->PushToStack();
- int const priority = Tags.FindI("Pin-Priority", 0);
+ std::string sPriority = Tags.FindS("Pin-Priority");
+ int priority = sPriority == "never" ? NEVER_PIN : Tags.FindI("Pin-Priority", 0);
bool const newError = _error->PendingError();
_error->MergeWithStack();
+
+ if (sPriority == "never" && not Name.empty())
+ return _error->Error(_("%s: The special 'Pin-Priority: %s' can only be used for 'Package: *' records"), File.c_str(), "never");
+
+ // Silently clamp the never pin to never pin + 1
+ if (priority == NEVER_PIN && sPriority != "never")
+ priority = NEVER_PIN + 1;
if (priority < std::numeric_limits<short>::min() ||
priority > std::numeric_limits<short>::max() ||
newError) {