a pin of 1000 always means downgrade allowed

The documentation says this, but the code only agreed while evaluating
specific packages, but not generics. These needed a pin above 1000 to
have the same effect.

The code causing this makes references to a 'second pesduo status file',
but nowhere is explained what this might stand for and/or what it was,
so we do the only reasonable thing: Remove all references and do as
documented.

apt-pkg/policy.cc

@@ -4,22 +4,12 @@
 /* ######################################################################
 
    Package Version Policy implementation
-   
+
    This is just a really simple wrapper around pkgVersionMatch with
    some added goodies to manage the list of things..
-   
-   Priority Table:
-   
-   1000 -> inf = Downgradeable priorities
-   1000        = The 'no downgrade' pseduo-status file
-   100 -> 1000 = Standard priorities
-   990         = Config file override package files
-   989         = Start for preference auto-priorities
-   500         = Default package files
-   100         = The status file and ButAutomaticUpgrades sources
-   0 -> 100    = NotAutomatic sources like experimental
-   -inf -> 0   = Never selected   
-   
+
+   See man apt_preferences for what value means what.
+
    ##################################################################### */
 									/*}}}*/
 // Include Files							/*{{{*/
@@ -56,7 +46,7 @@ using namespace std;
    file matches the V0 policy engine. */
 pkgPolicy::pkgPolicy(pkgCache *Owner) : Pins(0), PFPriority(0), Cache(Owner)
 {
-   if (Owner == 0 || &(Owner->Head()) == 0)
+   if (Owner == 0)
       return;
    PFPriority = new signed short[Owner->Head().PackageFileCount];
    Pins = new Pin[Owner->Head().PackageCount];
@@ -125,7 +115,7 @@ bool pkgPolicy::InitDefaults()
 	    else
 	       PFPriority[F->ID] = Cur;
 	    
-	    if (PFPriority[F->ID] > 1000)
+	    if (PFPriority[F->ID] >= 1000)
 	       StatusOverride = true;
 	    
 	    Fixed[F->ID] = true;
@@ -166,9 +156,7 @@ pkgCache::VerIterator pkgPolicy::GetCandidateVer(pkgCache::PkgIterator const &Pk
       effectively excludes everything <= 0 which are the non-automatic
       priorities.. The status file is given a prio of 100 which will exclude
       not-automatic sources, except in a single shot not-installed mode.
-      The second pseduo-status file is at prio 1000, above which will permit
-      the user to force-downgrade things.
-      
+
       The user pin is subject to the same priority rules as default 
       selections. Thus there are two ways to create a pin - a pin that
       tracks the default when the default is taken away, and a permanent
@@ -218,9 +206,9 @@ pkgCache::VerIterator pkgPolicy::GetCandidateVer(pkgCache::PkgIterator const &Pk
 	    Pref = Ver;
 	    PrefSeen = true;
 	 }
-	 /* Elevate our current selection (or the status file itself)
-	    to the Pseudo-status priority. */
-	 Max = 1000;
+	 /* Elevate our current selection (or the status file itself) so that only
+	    a downgrade can override it from now on */
+	 Max = 999;
 
 	 // Fast path optimize.
 	 if (StatusOverride == false)

test/integration/test-bug-543966-downgrade-below-1000-pin

@@ -24,58 +24,66 @@ testsuccessequal "base-files:
      5.0.0 0
         500 file:${APTARCHIVE} unstable/main i386 Packages" aptcache policy base-files -o apt::pin=0
 
-echo 'Package: base-files
+writepin() {
+	echo "Package: $1
 Pin: release a=unstable
-Pin-Priority: 99' > rootdir/etc/apt/preferences
+Pin-Priority: $2" > rootdir/etc/apt/preferences
+}
 
-testsuccessequal "base-files:
+
+
+testpinning() {
+	local PKGPIN=''
+	local PKGPINPRIO='0'
+	local REPPINPRIO=''
+	if [ "$1" != '*' ]; then
+		PKGPINPRIO=''
+		REPPINPRIO=' 500'
+		PKGPIN='Package pin: 5.0.0
+  '
+	fi
+	writepin "$1" '99'
+	testsuccessequal "base-files:
   Installed: 5.0.0-1
   Candidate: 5.0.0-1
-  Package pin: 5.0.0
-  Version table:
- *** 5.0.0-1 99
+  ${PKGPIN}Version table:
+ *** 5.0.0-1 ${PKGPINPRIO:-99}
         100 $STATUS
-     5.0.0 99
-        500 file:${APTARCHIVE} unstable/main i386 Packages" aptcache policy base-files -o apt::pin=99
+     5.0.0 ${PKGPINPRIO:-99}
+       ${REPPINPRIO:-  99} file:${APTARCHIVE} unstable/main i386 Packages" aptcache policy base-files -o apt::pin=99
 
-echo 'Package: base-files
-Pin: release a=unstable
-Pin-Priority: 100' > rootdir/etc/apt/preferences
-
-testsuccessequal "base-files:
+	writepin "$1" '100'
+	testsuccessequal "base-files:
   Installed: 5.0.0-1
   Candidate: 5.0.0-1
-  Package pin: 5.0.0
-  Version table:
- *** 5.0.0-1 100
+  ${PKGPIN}Version table:
+ *** 5.0.0-1 ${PKGPINPRIO:-100}
         100 $STATUS
-     5.0.0 100
-        500 file:${APTARCHIVE} unstable/main i386 Packages" aptcache policy base-files -o apt::pin=100
+     5.0.0 ${PKGPINPRIO:-100}
+       ${REPPINPRIO:- 100} file:${APTARCHIVE} unstable/main i386 Packages" aptcache policy base-files -o apt::pin=100
 
-echo 'Package: base-files
-Pin: release a=unstable
-Pin-Priority: 999' > rootdir/etc/apt/preferences
-
-testsuccessequal "base-files:
+	writepin "$1" '999'
+	testsuccessequal "base-files:
   Installed: 5.0.0-1
   Candidate: 5.0.0-1
-  Package pin: 5.0.0
-  Version table:
- *** 5.0.0-1 999
+  ${PKGPIN}Version table:
+ *** 5.0.0-1 ${PKGPINPRIO:-999}
         100 $STATUS
-     5.0.0 999
-        500 file:${APTARCHIVE} unstable/main i386 Packages" aptcache policy base-files -o apt::pin=999
-
-echo 'Package: base-files
-Pin: release a=unstable
-Pin-Priority: 1000' > rootdir/etc/apt/preferences
+     5.0.0 ${PKGPINPRIO:-999}
+       ${REPPINPRIO:- 999} file:${APTARCHIVE} unstable/main i386 Packages" aptcache policy base-files -o apt::pin=999
 
-testsuccessequal "base-files:
+	writepin "$1" '1000'
+	testsuccessequal "base-files:
   Installed: 5.0.0-1
   Candidate: 5.0.0
-  Package pin: 5.0.0
-  Version table:
- *** 5.0.0-1 1000
+  ${PKGPIN}Version table:
+ *** 5.0.0-1 ${PKGPINPRIO:-1000}
         100 $STATUS
-     5.0.0 1000
-        500 file:${APTARCHIVE} unstable/main i386 Packages" aptcache policy base-files -o apt::pin=1000
+     5.0.0 ${PKGPINPRIO:-1000}
+       ${REPPINPRIO:-1000} file:${APTARCHIVE} unstable/main i386 Packages" aptcache policy base-files -o apt::pin=1000
+}
+
+msgmsg 'Tests with generic-form pin'
+testpinning '*'
+msgmsg 'Tests with specific-form pin'
+testpinning 'base-files'

test/integration/test-policy-pinning

@@ -25,70 +25,58 @@ testequalpolicy() {
 Pinned packages:" aptcache policy $*
 }
 
-aptgetupdate() {
-	# just to be sure that no old files are used
-	rm -rf rootdir/var/lib/apt
-	if aptget update  --allow-insecure-repositories -qq 2>&1 | grep '^E: '; then
-		msgwarn 'apt-get update failed with an error'
-	fi
-}
+testglobalpolicy() {
+	aptgetupdate
 
-### not signed archive
+	testequalpolicy 100 500
+	testequalpolicy 990 500 -t now
 
-aptgetupdate
+	sed -i aptarchive/Release -e 1i"NotAutomatic: yes"
+	aptgetupdate
 
-testequalpolicy 100 500
-testequalpolicy 990 500 -t now
+	testequalpolicy 100 1 -o Test=NotAutomatic
+	testequalpolicy 990 1 -o Test=NotAutomatic -t now
 
-sed -i aptarchive/Release -e 1i"NotAutomatic: yes"
-aptgetupdate
+	sed -i aptarchive/Release -e 1i"ButAutomaticUpgrades: yes"
+	aptgetupdate
 
-testequalpolicy 100 1 -o Test=NotAutomatic
-testequalpolicy 990 1 -o Test=NotAutomatic -t now
+	testequalpolicy 100 100 -o Test=ButAutomaticUpgrades
+	testequalpolicy 990 100 -o Test=ButAutomaticUpgrades -t now
 
-sed -i aptarchive/Release -e 1i"ButAutomaticUpgrades: yes"
-aptgetupdate
+	sed -i aptarchive/Release -e 's#NotAutomatic: yes#NotAutomatic: no#' -e '/ButAutomaticUpgrades: / d'
+	aptgetupdate
 
-testequalpolicy 100 100 -o Test=ButAutomaticUpgrades
-testequalpolicy 990 100 -o Test=ButAutomaticUpgrades -t now
+	testequalpolicy 100 500 -o Test=Automatic
+	testequalpolicy 990 500 -o Test=Automatic -t now
 
-sed -i aptarchive/Release -e 's#NotAutomatic: yes#NotAutomatic: no#' -e '/ButAutomaticUpgrades: / d'
-aptgetupdate
-
-testequalpolicy 100 500 -o Test=Automatic
-testequalpolicy 990 500 -o Test=Automatic -t now
-
-sed -i aptarchive/Release -e '/NotAutomatic: / d' -e '/ButAutomaticUpgrades: / d'
-
-### signed but no key in trusted
-
-signreleasefiles 'Marvin Paranoid'
-aptgetupdate
-testequalpolicy 100 500
-testequalpolicy 990 500 -t now
-
-sed -i aptarchive/Release -e 1i"NotAutomatic: yes"
-signreleasefiles 'Marvin Paranoid'
-aptgetupdate
-
-testequalpolicy 100 1 -o Test=NotAutomatic
-testequalpolicy 990 1 -o Test=NotAutomatic -t now
-
-sed -i aptarchive/Release -e 1i"ButAutomaticUpgrades: yes"
-signreleasefiles 'Marvin Paranoid'
-aptgetupdate
+	sed -i aptarchive/Release -e '/NotAutomatic: / d' -e '/ButAutomaticUpgrades: / d'
+}
 
-testequalpolicy 100 100 -o Test=ButAutomaticUpgrades
-testequalpolicy 990 100 -o Test=ButAutomaticUpgrades -t now
+msgmsg 'Test with not signed archive'
+aptgetupdate() {
+	rm -rf rootdir/var/lib/apt
+	testwarning aptget update  --allow-insecure-repositories
+}
+testglobalpolicy
 
-sed -i aptarchive/Release -e 's#NotAutomatic: yes#NotAutomatic: no#' -e '/ButAutomaticUpgrades: / d'
-signreleasefiles 'Marvin Paranoid'
-aptgetupdate
+msgmsg 'Test with signed but no key in trusted'
+aptgetupdate() {
+	rm -rf rootdir/var/lib/apt
+	signreleasefiles 'Marvin Paranoid'
+	testwarning aptget update  --allow-insecure-repositories
+}
+testglobalpolicy
 
-testequalpolicy 100 500 -o Test=Automatic
-testequalpolicy 990 500 -o Test=Automatic -t now
+# much the same tests will be executed below in more detail again for this one
+msgmsg 'Test with signed and valid key'
+aptgetupdate() {
+	rm -rf rootdir/var/lib/apt
+	signreleasefiles 'Joe Sixpack'
+	testsuccess aptget update
+}
+testglobalpolicy
 
-### signed and valid key
+msgmsg 'Test with specific packages'
 
 buildsimplenativepackage "coolstuff" "all" "1.0" "stable"
 buildsimplenativepackage "coolstuff" "all" "2.0~bpo1" "backports"