X-Git-Url: http://review.tizen.org/git/?a=blobdiff_plain;f=src%2Fpolicy.c;h=6287b7c64e4abd6df2ffd9bf021f9217c5a2b55c;hb=673b10389cfdea7282d2587a00a01c9b0cf713d9;hp=603df682a976ee2d9eb73ab2b34e9ae3146810f7;hpb=ff97f9a46d8c161971acdf384f9dfb037d3098f5;p=platform%2Fupstream%2Flibsolv.git

diff --git a/src/policy.c b/src/policy.c
index 603df68..6287b7c 100644
--- a/src/policy.c
+++ b/src/policy.c
@@ -1,30 +1,1003 @@
 /*
- * Generic policy interface for SAT solver
- * 
+ * Copyright (c) 2007, Novell Inc.
+ *
+ * This program is licensed under the BSD license, read LICENSE.BSD
+ * for further information
  */
 
-#include "solver.h"
+/*
+ * Generic policy interface for SAT solver
+ *
+ */
 
 #include <stdio.h>
+#include <stdlib.h>
+#include <unistd.h>
+#include <string.h>
+
+#include "solver.h"
+#include "solver_private.h"
+#include "evr.h"
 #include "policy.h"
+#include "poolvendor.h"
+#include "poolarch.h"
 
-int
-policy_init( const Pool *p )
+
+/*-----------------------------------------------------------------*/
+
+/*
+ * prep for prune_best_version
+ *   sort by name
+ */
+
+static int
+prune_to_best_version_sortcmp(const void *ap, const void *bp, void *dp)
 {
-  return 0;
+  Pool *pool = dp;
+  int r;
+  Id a = *(Id *)ap;
+  Id b = *(Id *)bp;
+  Solvable *sa, *sb;
+
+  sa = pool->solvables + a;
+  sb = pool->solvables + b;
+  r = sa->name - sb->name;
+  if (r)
+    {
+      const char *na, *nb;
+      /* different names. We use real strcmp here so that the result
+       * is not depending on some random solvable order */
+      na = pool_id2str(pool, sa->name);
+      nb = pool_id2str(pool, sb->name);
+      return strcmp(na, nb);
+    }
+  if (sa->arch != sb->arch)
+    {
+      int aa, ab;
+      aa = (sa->arch <= pool->lastarch) ? pool->id2arch[sa->arch] : 0;
+      ab = (sb->arch <= pool->lastarch) ? pool->id2arch[sb->arch] : 0;
+      if (aa != ab && aa > 1 && ab > 1)
+	return aa - ab;		/* lowest score first */
+    }
+
+  /* the same name, bring installed solvables to the front */
+  if (pool->installed)
+    {
+      if (sa->repo == pool->installed)
+	{
+	  if (sb->repo != pool->installed)
+	    return -1;
+	}
+      else if (sb->repo == pool->installed)
+	return 1;	
+    }
+  /* sort by repository sub-prio (installed repo handled above) */
+  r = (sb->repo ? sb->repo->subpriority : 0) - (sa->repo ? sa->repo->subpriority : 0);
+  if (r)
+    return r;
+  /* no idea about the order, sort by id */
+  return a - b;
 }
 
 
+/*
+ * prune to repository with highest priority.
+ * does not prune installed solvables.
+ */
+
+static void
+prune_to_highest_prio(Pool *pool, Queue *plist)
+{
+  int i, j;
+  Solvable *s;
+  int bestprio = 0, bestprioset = 0;
+
+  /* prune to highest priority */
+  for (i = 0; i < plist->count; i++)  /* find highest prio in queue */
+    {
+      s = pool->solvables + plist->elements[i];
+      if (pool->installed && s->repo == pool->installed)
+	continue;
+      if (!bestprioset || s->repo->priority > bestprio)
+	{
+	  bestprio = s->repo->priority;
+	  bestprioset = 1;
+	}
+    }
+  if (!bestprioset)
+    return;
+  for (i = j = 0; i < plist->count; i++) /* remove all with lower prio */
+    {
+      s = pool->solvables + plist->elements[i];
+      if (s->repo->priority == bestprio || (pool->installed && s->repo == pool->installed))
+	plist->elements[j++] = plist->elements[i];
+    }
+  plist->count = j;
+}
+
+
+/* installed packages involed in a dup operation can only be kept
+ * if they are identical to a non-installed one */
+static void
+solver_prune_installed_dup_packages(Solver *solv, Queue *plist)
+{
+  Pool *pool = solv->pool;
+  int i, j, bestprio = 0;
+
+  /* find bestprio (again) */
+  for (i = 0; i < plist->count; i++)
+    {
+      Solvable *s = pool->solvables + plist->elements[i];
+      if (s->repo != pool->installed)
+	{
+	  bestprio = s->repo->priority;
+	  break;
+	}
+    }
+  if (i == plist->count)
+    return;	/* only installed packages, could not find prio */
+  for (i = j = 0; i < plist->count; i++)
+    {
+      Id p = plist->elements[i];
+      Solvable *s = pool->solvables + p;
+      if (s->repo != pool->installed && s->repo->priority < bestprio)
+	continue;
+      if (s->repo == pool->installed && (solv->dupmap_all || (solv->dupinvolvedmap.size && MAPTST(&solv->dupinvolvedmap, p))))
+	{
+	  Id p2, pp2;
+	  int keepit = 0;
+	  FOR_PROVIDES(p2, pp2, s->name)
+	    {
+	      Solvable *s2 = pool->solvables + p2;
+	      if (s2->repo == pool->installed || s2->evr != s->evr || s2->repo->priority < bestprio)
+		continue;
+	      if (!solvable_identical(s, s2))
+		continue;
+	      keepit = 1;
+	      if (s2->repo->priority > bestprio)
+		{
+		  /* new max prio! */
+		  bestprio = s2->repo->priority;
+		  j = 0;
+		}
+	    }
+	  if (!keepit)
+	    continue;	/* no identical package found, ignore installed package */
+	}
+      plist->elements[j++] = p;
+    }
+  if (j)
+    plist->count = j;
+}
+
+/*
+ * like prune_to_highest_prio, but calls solver prune_installed_dup_packages
+ * when there are dup packages
+ */
+static inline void
+solver_prune_to_highest_prio(Solver *solv, Queue *plist)
+{
+  prune_to_highest_prio(solv->pool, plist);
+  if (plist->count > 1 && solv->pool->installed && (solv->dupmap_all || solv->dupinvolvedmap.size))
+    solver_prune_installed_dup_packages(solv, plist);
+}
+
+
+static void
+solver_prune_to_highest_prio_per_name(Solver *solv, Queue *plist)
+{
+  Pool *pool = solv->pool;
+  Queue pq;
+  int i, j, k;
+  Id name;
+
+  queue_init(&pq);
+  solv_sort(plist->elements, plist->count, sizeof(Id), prune_to_best_version_sortcmp, pool);
+  queue_push(&pq, plist->elements[0]);
+  name = pool->solvables[pq.elements[0]].name;
+  for (i = 1, j = 0; i < plist->count; i++)
+    {
+      if (pool->solvables[plist->elements[i]].name != name)
+	{
+	  if (pq.count > 2)
+	    solver_prune_to_highest_prio(solv, &pq);
+	  for (k = 0; k < pq.count; k++)
+	    plist->elements[j++] = pq.elements[k];
+	  queue_empty(&pq);
+	  queue_push(&pq, plist->elements[i]);
+	  name = pool->solvables[pq.elements[0]].name;
+	}
+    }
+  if (pq.count > 2)
+    solver_prune_to_highest_prio(solv, &pq);
+  for (k = 0; k < pq.count; k++)
+    plist->elements[j++] = pq.elements[k];
+  queue_free(&pq);
+  plist->count = j;
+}
+
+
+/*
+ * prune to recommended/suggested packages.
+ * does not prune installed packages (they are also somewhat recommended).
+ */
+
+static void
+prune_to_recommended(Solver *solv, Queue *plist)
+{
+  Pool *pool = solv->pool;
+  int i, j, k, ninst;
+  Solvable *s;
+  Id p, pp, rec, *recp, sug, *sugp;
+
+  ninst = 0;
+  if (pool->installed)
+    {
+      for (i = 0; i < plist->count; i++)
+	{
+	  p = plist->elements[i];
+	  s = pool->solvables + p;
+	  if (pool->installed && s->repo == pool->installed)
+	    ninst++;
+	}
+    }
+  if (plist->count - ninst < 2)
+    return;
+
+  /* update our recommendsmap/suggestsmap */
+  if (solv->recommends_index < 0)
+    {
+      MAPZERO(&solv->recommendsmap);
+      MAPZERO(&solv->suggestsmap);
+      solv->recommends_index = 0;
+    }
+  while (solv->recommends_index < solv->decisionq.count)
+    {
+      p = solv->decisionq.elements[solv->recommends_index++];
+      if (p < 0)
+	continue;
+      s = pool->solvables + p;
+      if (s->recommends)
+	{
+	  recp = s->repo->idarraydata + s->recommends;
+          while ((rec = *recp++) != 0)
+	    FOR_PROVIDES(p, pp, rec)
+	      MAPSET(&solv->recommendsmap, p);
+	}
+      if (s->suggests)
+	{
+	  sugp = s->repo->idarraydata + s->suggests;
+          while ((sug = *sugp++) != 0)
+	    FOR_PROVIDES(p, pp, sug)
+	      MAPSET(&solv->suggestsmap, p);
+	}
+    }
+
+  /* prune to recommended/supplemented */
+  ninst = 0;
+  for (i = j = 0; i < plist->count; i++)
+    {
+      p = plist->elements[i];
+      s = pool->solvables + p;
+      if (pool->installed && s->repo == pool->installed)
+	{
+	  ninst++;
+	  if (j)
+	    plist->elements[j++] = p;
+	  continue;
+	}
+      if (!MAPTST(&solv->recommendsmap, p))
+	if (!solver_is_supplementing(solv, s))
+	  continue;
+      if (!j && ninst)
+	{
+	  for (k = 0; j < ninst; k++)
+	    {
+	      s = pool->solvables + plist->elements[k];
+	      if (pool->installed && s->repo == pool->installed)
+	        plist->elements[j++] = plist->elements[k];
+	    }
+	}
+      plist->elements[j++] = p;
+    }
+  if (j)
+    plist->count = j;
+
+  /* anything left to prune? */
+  if (plist->count - ninst < 2)
+    return;
+
+  /* prune to suggested/enhanced */
+  ninst = 0;
+  for (i = j = 0; i < plist->count; i++)
+    {
+      p = plist->elements[i];
+      s = pool->solvables + p;
+      if (pool->installed && s->repo == pool->installed)
+	{
+	  ninst++;
+	  if (j)
+	    plist->elements[j++] = p;
+	  continue;
+	}
+      if (!MAPTST(&solv->suggestsmap, p))
+        if (!solver_is_enhancing(solv, s))
+	  continue;
+      if (!j && ninst)
+	{
+	  for (k = 0; j < ninst; k++)
+	    {
+	      s = pool->solvables + plist->elements[k];
+	      if (pool->installed && s->repo == pool->installed)
+	        plist->elements[j++] = plist->elements[k];
+	    }
+	}
+      plist->elements[j++] = p;
+    }
+  if (j)
+    plist->count = j;
+}
+
+static void
+prune_to_best_arch(const Pool *pool, Queue *plist)
+{
+  Id a, bestscore;
+  Solvable *s;
+  int i, j;
+
+  if (!pool->id2arch || plist->count < 2)
+    return;
+  bestscore = 0;
+  for (i = 0; i < plist->count; i++)
+    {
+      s = pool->solvables + plist->elements[i];
+      a = s->arch;
+      a = (a <= pool->lastarch) ? pool->id2arch[a] : 0;
+      if (a && a != 1 && (!bestscore || a < bestscore))
+	bestscore = a;
+    }
+  if (!bestscore)
+    return;
+  for (i = j = 0; i < plist->count; i++)
+    {
+      s = pool->solvables + plist->elements[i];
+      a = s->arch;
+      if (a > pool->lastarch)
+	continue;
+      a = pool->id2arch[a];
+      /* a == 1 -> noarch */
+      if (a != 1 && ((a ^ bestscore) & 0xffff0000) != 0)
+	continue;
+      plist->elements[j++] = plist->elements[i];
+    }
+  if (j)
+    plist->count = j;
+}
+
+
+struct trj_data {
+  Pool *pool;
+  Queue *plist;
+  Id *stack;
+  Id nstack;
+  Id *low;
+  Id firstidx;
+  Id idx;
+};
+
+/* This is Tarjan's SCC algorithm, slightly modified */
+static void
+trj_visit(struct trj_data *trj, Id node)
+{
+  Id *low = trj->low;
+  Pool *pool = trj->pool;
+  Queue *plist = trj->plist;
+  Id myidx, stackstart;
+  Solvable *s;
+  int i;
+  Id p, pp, obs, *obsp;
+
+  low[node] = myidx = trj->idx++;
+  trj->stack[(stackstart = trj->nstack++)] = node;
+
+  s = pool->solvables + plist->elements[node];
+  if (s->obsoletes)
+    {
+      obsp = s->repo->idarraydata + s->obsoletes;
+      while ((obs = *obsp++) != 0)
+	{
+	  FOR_PROVIDES(p, pp, obs)
+	    {
+	      Solvable *ps = pool->solvables + p;
+	      if (ps->name == s->name)
+		continue;
+	      if (!pool->obsoleteusesprovides && !pool_match_nevr(pool, ps, obs))
+		continue;
+	      if (pool->obsoleteusescolors && !pool_colormatch(pool, s, ps))
+		continue;
+	      /* hmm, expensive. should use hash if plist is big */
+	      for (i = 0; i < plist->count; i++)
+		{
+		  if (node != i && plist->elements[i] == p)
+		    {
+		      Id l = low[i];
+		      if (!l)
+			{
+			  if (!ps->obsoletes)
+			    {
+			      /* don't bother */
+			      trj->idx++;
+			      low[i] = -1;
+			      continue;
+			    }
+			  trj_visit(trj, i);
+			  l = low[i];
+			}
+		      if (l < 0)
+			continue;
+		      if (l < trj->firstidx)
+			{
+			  int k;
+			  /* this means we have reached an old SCC found earlier.
+			   * delete it as we obsolete it */
+			  for (k = l; ; k++)
+			    {
+			      if (low[trj->stack[k]] == l)
+				low[trj->stack[k]] = -1;
+			      else
+				break;
+			    }
+			}
+		      else if (l < low[node])
+			low[node] = l;
+		    }
+		}
+	    }
+	}
+    }
+  if (low[node] == myidx)	/* found a SCC? */
+    {
+      /* we're only interested in SCCs that contain the first node,
+       * as all others are "obsoleted" */
+      if (myidx != trj->firstidx)
+	myidx = -1;
+      for (i = stackstart; i < trj->nstack; i++)
+	low[trj->stack[i]] = myidx;
+      trj->nstack = stackstart;	/* empty stack */
+    }
+}
+
+/*
+ * remove entries from plist that are obsoleted by other entries
+ * with different name.
+ */
+static void
+prune_obsoleted(Pool *pool, Queue *plist)
+{
+  Id data_buf[2 * 16], *data;
+  struct trj_data trj;
+  int i, j;
+  Solvable *s;
+
+  if (plist->count <= 16)
+    {
+      memset(data_buf, 0, sizeof(data_buf));
+      data = data_buf;
+    }
+  else
+    data = solv_calloc(plist->count, 2 * sizeof(Id));
+  trj.pool = pool;
+  trj.plist = plist;
+  trj.low = data;
+  trj.idx = 1;
+  trj.stack = data + plist->count - 1;	/* -1 so we can index with idx (which starts with 1) */
+  for (i = 0; i < plist->count; i++)
+    {
+      if (trj.low[i])
+	continue;
+      s = pool->solvables + plist->elements[i];
+      if (s->obsoletes)
+	{
+	  trj.firstidx = trj.nstack = trj.idx;
+          trj_visit(&trj, i);
+	}
+      else
+        {
+          Id myidx = trj.idx++;
+          trj.low[i] = myidx;
+          trj.stack[myidx] = i;
+        }
+    }
+  for (i = j = 0; i < plist->count; i++)
+    if (trj.low[i] >= 0)
+      plist->elements[j++] = plist->elements[i];
+  plist->count = j;
+  if (data != data_buf)
+    solv_free(data);
+}
+
+/* this is prune_obsoleted special-cased for two elements */
+static void
+prune_obsoleted_2(Pool *pool, Queue *plist)
+{
+  int i;
+  Solvable *s;
+  Id p, pp, obs, *obsp;
+  Id other;
+  int obmap = 0;
+
+  for (i = 0; i < 2; i++)
+    {
+      s = pool->solvables + plist->elements[i];
+      other = plist->elements[1 - i];
+      if (s->obsoletes)
+	{
+	  obsp = s->repo->idarraydata + s->obsoletes;
+	  while ((obs = *obsp++) != 0)
+	    {
+	      FOR_PROVIDES(p, pp, obs)
+		{
+		  Solvable *ps;
+		  if (p != other)
+		    continue;
+		  ps = pool->solvables + p;
+		  if (ps->name == s->name)
+		    continue;
+		  if (!pool->obsoleteusesprovides && !pool_match_nevr(pool, ps, obs))
+		    continue;
+		  if (pool->obsoleteusescolors && !pool_colormatch(pool, s, ps))
+		    continue;
+		  obmap |= 1 << i;
+		  break;
+		}
+	      if (p)
+		break;
+	    }
+	}
+    }
+  if (obmap == 0 || obmap == 3)
+    return;
+  if (obmap == 2)
+    plist->elements[0] = plist->elements[1];
+  plist->count = 1;
+}
+
+/*
+ * bring those elements to the front of the queue that
+ * have a installed solvable with the same name
+ */
+static void
+move_installed_to_front(Pool *pool, Queue *plist)
+{
+  int i, j;
+  Solvable *s;
+  Id p, pp;
+
+  for (i = j = 0; i < plist->count; i++)
+    {
+      s = pool->solvables + plist->elements[i];
+      if (s->repo != pool->installed)
+        {
+          FOR_PROVIDES(p, pp, s->name)
+	    {
+	      Solvable *ps = pool->solvables + p;
+	      if (s->name == ps->name && ps->repo == pool->installed)
+		{
+		  s = ps;
+		  break;
+		}
+	    }
+        }
+      if (s->repo == pool->installed)
+	{
+	  if (i != j)
+	    {
+	      p = plist->elements[i];
+              if (i - j == 1)
+		plist->elements[i] = plist->elements[j];
+	      else
+	        memmove(plist->elements + j + 1, plist->elements + j, (i - j) * sizeof(Id));
+	      plist->elements[j] = p;
+	    }
+	  else if (j + 2 == plist->count)
+	    break;	/* no need to check last element if all prev ones are installed */
+	  j++;
+	}
+    }
+}
+
+/*
+ * prune_to_best_version
+ *
+ * sort list of packages (given through plist) by name and evr
+ * return result through plist
+ */
+static void
+prune_to_best_version(Pool *pool, Queue *plist)
+{
+  int i, j;
+  Solvable *s, *best;
+
+  if (plist->count < 2)		/* no need to prune for a single entry */
+    return;
+  POOL_DEBUG(SOLV_DEBUG_POLICY, "prune_to_best_version %d\n", plist->count);
+
+  /* sort by name first, prefer installed */
+  solv_sort(plist->elements, plist->count, sizeof(Id), prune_to_best_version_sortcmp, pool);
+
+  /* now find best 'per name' */
+  best = 0;
+  for (i = j = 0; i < plist->count; i++)
+    {
+      s = pool->solvables + plist->elements[i];
+
+      POOL_DEBUG(SOLV_DEBUG_POLICY, "- %s[%s]\n",
+		 pool_solvable2str(pool, s),
+		 (pool->installed && s->repo == pool->installed) ? "installed" : "not installed");
+
+      if (!best)		/* if no best yet, the current is best */
+        {
+          best = s;
+          continue;
+        }
+
+      /* name switch: finish group, re-init */
+      if (best->name != s->name)   /* new name */
+        {
+          plist->elements[j++] = best - pool->solvables; /* move old best to front */
+          best = s;		/* take current as new best */
+          continue;
+        }
+
+      if (best->evr != s->evr)	/* compare evr */
+        {
+          if (pool_evrcmp(pool, best->evr, s->evr, EVRCMP_COMPARE) < 0)
+            best = s;
+        }
+    }
+  plist->elements[j++] = best - pool->solvables;	/* finish last group */
+  plist->count = j;
+
+  /* we reduced the list to one package per name, now look at
+   * package obsoletes */
+  if (plist->count > 1)
+    {
+      if (plist->count == 2)
+        prune_obsoleted_2(pool, plist);
+      else
+        prune_obsoleted(pool, plist);
+    }
+  if (plist->count > 1 && pool->installed)
+    move_installed_to_front(pool, plist);
+}
+
+
+/*
+ *  POLICY_MODE_CHOOSE:     default, do all pruning steps
+ *  POLICY_MODE_RECOMMEND:  leave out prune_to_recommended
+ *  POLICY_MODE_SUGGEST:    leave out prune_to_recommended, do prio pruning just per name
+ */
+void
+policy_filter_unwanted(Solver *solv, Queue *plist, int mode)
+{
+  Pool *pool = solv->pool;
+  if (plist->count > 1)
+    {
+      if (mode != POLICY_MODE_SUGGEST)
+        solver_prune_to_highest_prio(solv, plist);
+      else
+        solver_prune_to_highest_prio_per_name(solv, plist);
+    }
+  if (plist->count > 1)
+    prune_to_best_arch(pool, plist);
+  if (plist->count > 1)
+    prune_to_best_version(pool, plist);
+  if (plist->count > 1 && mode == POLICY_MODE_CHOOSE)
+    prune_to_recommended(solv, plist);
+}
+
+
+/* check if there is an illegal architecture change if
+ * installed solvable s1 is replaced by s2 */
 int
-policy_exit( void )
+policy_illegal_archchange(Solver *solv, Solvable *s1, Solvable *s2)
 {
+  Pool *pool = solv->pool;
+  Id a1 = s1->arch, a2 = s2->arch;
+
+  /* we allow changes to/from noarch */
+  if (a1 == a2 || a1 == pool->noarchid || a2 == pool->noarchid)
+    return 0;
+  if (!pool->id2arch)
+    return 0;
+  a1 = a1 <= pool->lastarch ? pool->id2arch[a1] : 0;
+  a2 = a2 <= pool->lastarch ? pool->id2arch[a2] : 0;
+  if (((a1 ^ a2) & 0xffff0000) != 0)
+    return 1;
   return 0;
 }
 
-/*-----------------------------------------------*/
+/* check if there is an illegal vendor change if
+ * installed solvable s1 is replaced by s2 */
 int
-policy_printrules( void )
+policy_illegal_vendorchange(Solver *solv, Solvable *s1, Solvable *s2)
 {
-  /* default: false */
-  return 0;
+  Pool *pool = solv->pool;
+  Id v1, v2;
+  Id vendormask1, vendormask2;
+
+  if (pool->custom_vendorcheck)
+     return pool->custom_vendorcheck(pool, s1, s2);
+
+  /* treat a missing vendor as empty string */
+  v1 = s1->vendor ? s1->vendor : ID_EMPTY;
+  v2 = s2->vendor ? s2->vendor : ID_EMPTY;
+  if (v1 == v2)
+    return 0;
+  vendormask1 = pool_vendor2mask(pool, v1);
+  if (!vendormask1)
+    return 1;	/* can't match */
+  vendormask2 = pool_vendor2mask(pool, v2);
+  if ((vendormask1 & vendormask2) != 0)
+    return 0;
+  return 1;	/* no class matches */
+}
+
+/* check if it is illegal to replace installed
+ * package "is" with package "s" (which must obsolete "is")
+ */
+int
+policy_is_illegal(Solver *solv, Solvable *is, Solvable *s, int ignore)
+{
+  Pool *pool = solv->pool;
+  int ret = 0;
+  int duppkg = solv->dupmap_all ? 1 : 0;
+  if (!(ignore & POLICY_ILLEGAL_DOWNGRADE) && !(duppkg ? solv->dup_allowdowngrade : solv->allowdowngrade))
+    {
+      if (is->name == s->name && pool_evrcmp(pool, is->evr, s->evr, EVRCMP_COMPARE) > 0)
+	ret |= POLICY_ILLEGAL_DOWNGRADE;
+    }
+  if (!(ignore & POLICY_ILLEGAL_ARCHCHANGE) && !(duppkg ? solv->dup_allowarchchange : solv->allowarchchange))
+    {
+      if (is->arch != s->arch && policy_illegal_archchange(solv, is, s))
+	ret |= POLICY_ILLEGAL_ARCHCHANGE;
+    }
+  if (!(ignore & POLICY_ILLEGAL_VENDORCHANGE) && !(duppkg ? solv->dup_allowvendorchange : solv->allowvendorchange))
+    {
+      if (is->vendor != s->vendor && policy_illegal_vendorchange(solv, is, s))
+	ret |= POLICY_ILLEGAL_VENDORCHANGE;
+    }
+  if (!(ignore & POLICY_ILLEGAL_NAMECHANGE) && !(duppkg ? solv->dup_allownamechange : solv->allownamechange))
+    {
+      if (is->name != s->name)
+	ret |= POLICY_ILLEGAL_NAMECHANGE;
+    }
+  return ret;
 }
+
+/*-------------------------------------------------------------------
+ *
+ * create reverse obsoletes map for installed solvables
+ *
+ * For each installed solvable find which packages with *different* names
+ * obsolete the solvable.
+ * This index is used in policy_findupdatepackages() below.
+ */
+void
+policy_create_obsolete_index(Solver *solv)
+{
+  Pool *pool = solv->pool;
+  Solvable *s;
+  Repo *installed = solv->installed;
+  Id p, pp, obs, *obsp, *obsoletes, *obsoletes_data;
+  int i, n, cnt;
+
+  solv->obsoletes = solv_free(solv->obsoletes);
+  solv->obsoletes_data = solv_free(solv->obsoletes_data);
+  if (!installed || installed->start == installed->end)
+    return;
+  cnt = installed->end - installed->start;
+  solv->obsoletes = obsoletes = solv_calloc(cnt, sizeof(Id));
+  for (i = 1; i < pool->nsolvables; i++)
+    {
+      s = pool->solvables + i;
+      if (!s->obsoletes)
+	continue;
+      if (!pool_installable(pool, s))
+	continue;
+      obsp = s->repo->idarraydata + s->obsoletes;
+      while ((obs = *obsp++) != 0)
+	{
+	  FOR_PROVIDES(p, pp, obs)
+	    {
+	      Solvable *ps = pool->solvables + p;;
+	      if (ps->repo != installed)
+		continue;
+	      if (ps->name == s->name)
+		continue;
+	      if (!pool->obsoleteusesprovides && !pool_match_nevr(pool, ps, obs))
+		continue;
+	      if (pool->obsoleteusescolors && !pool_colormatch(pool, s, ps))
+		continue;
+	      obsoletes[p - installed->start]++;
+	    }
+	}
+    }
+  n = 0;
+  for (i = 0; i < cnt; i++)
+    if (obsoletes[i])
+      {
+        n += obsoletes[i] + 1;
+        obsoletes[i] = n;
+      }
+  solv->obsoletes_data = obsoletes_data = solv_calloc(n + 1, sizeof(Id));
+  POOL_DEBUG(SOLV_DEBUG_STATS, "obsoletes data: %d entries\n", n + 1);
+  for (i = pool->nsolvables - 1; i > 0; i--)
+    {
+      s = pool->solvables + i;
+      if (!s->obsoletes)
+	continue;
+      if (!pool_installable(pool, s))
+	continue;
+      obsp = s->repo->idarraydata + s->obsoletes;
+      while ((obs = *obsp++) != 0)
+	{
+	  FOR_PROVIDES(p, pp, obs)
+	    {
+	      Solvable *ps = pool->solvables + p;;
+	      if (ps->repo != installed)
+		continue;
+	      if (ps->name == s->name)
+		continue;
+	      if (!pool->obsoleteusesprovides && !pool_match_nevr(pool, ps, obs))
+		continue;
+	      if (pool->obsoleteusescolors && !pool_colormatch(pool, s, ps))
+		continue;
+	      if (obsoletes_data[obsoletes[p - installed->start]] != i)
+		obsoletes_data[--obsoletes[p - installed->start]] = i;
+	    }
+	}
+    }
+}
+
+
+/*
+ * find update candidates
+ *
+ * s: installed solvable to be updated
+ * qs: [out] queue to hold Ids of candidates
+ * allow_all: 0 = dont allow downgrades, 1 = allow all candidates
+ *            2 = dup mode
+ *
+ */
+void
+policy_findupdatepackages(Solver *solv, Solvable *s, Queue *qs, int allow_all)
+{
+  /* installed packages get a special upgrade allowed rule */
+  Pool *pool = solv->pool;
+  Id p, pp, n, p2, pp2;
+  Id obs, *obsp;
+  Solvable *ps;
+  int haveprovobs = 0;
+  int allowdowngrade = allow_all ? 1 : solv->allowdowngrade;
+  int allownamechange = allow_all ? 1 : solv->allownamechange;
+  int allowarchchange = allow_all ? 1 : solv->allowarchchange;
+  int allowvendorchange = allow_all ? 1 : solv->allowvendorchange;
+  if (allow_all == 2)
+    {
+      allowdowngrade = solv->dup_allowdowngrade;
+      allownamechange = solv->dup_allownamechange;
+      allowarchchange = solv->dup_allowarchchange;
+      allowvendorchange = solv->dup_allowvendorchange;
+    }
+
+  queue_empty(qs);
+
+  n = s - pool->solvables;
+
+  /*
+   * look for updates for s
+   */
+  FOR_PROVIDES(p, pp, s->name)	/* every provider of s' name */
+    {
+      if (p == n)		/* skip itself */
+	continue;
+
+      ps = pool->solvables + p;
+      if (s->name == ps->name)	/* name match */
+	{
+	  /* XXX: check implicitobsoleteusescolors? */
+	  if (!allowdowngrade && pool_evrcmp(pool, s->evr, ps->evr, EVRCMP_COMPARE) > 0)
+	    continue;
+	}
+      else if (!allownamechange)
+	continue;
+      else if (!solv->noupdateprovide && ps->obsoletes)   /* provides/obsoletes combination ? */
+	{
+	  obsp = ps->repo->idarraydata + ps->obsoletes;
+	  while ((obs = *obsp++) != 0)	/* for all obsoletes */
+	    {
+	      FOR_PROVIDES(p2, pp2, obs)   /* and all matching providers of the obsoletes */
+		{
+		  Solvable *ps2 = pool->solvables + p2;
+		  if (!pool->obsoleteusesprovides && !pool_match_nevr(pool, ps2, obs))
+		    continue;
+		  if (pool->obsoleteusescolors && !pool_colormatch(pool, s, ps2))
+		    continue;
+		  if (p2 == n)		/* match ! */
+		    break;
+		}
+	      if (p2)			/* match! */
+		break;
+	    }
+	  if (!obs)			/* continue if no match */
+	    continue;
+	  /* here we have 'p' with a matching provides/obsoletes combination
+	   * thus flagging p as a valid update candidate for s
+	   */
+	  haveprovobs = 1;
+	}
+      else
+        continue;
+      if (!allowarchchange && s->arch != ps->arch && policy_illegal_archchange(solv, s, ps))
+	continue;
+      if (!allowvendorchange && s->vendor != ps->vendor && policy_illegal_vendorchange(solv, s, ps))
+	continue;
+      queue_push(qs, p);
+    }
+  if (!allownamechange)
+    return;
+  /* if we have found some valid candidates and noupdateprovide is not set, we're
+     done. otherwise we fallback to all obsoletes */
+  if (!solv->noupdateprovide && haveprovobs)
+    return;
+  if (solv->obsoletes && solv->obsoletes[n - solv->installed->start])
+    {
+      Id *opp;
+      for (opp = solv->obsoletes_data + solv->obsoletes[n - solv->installed->start]; (p = *opp++) != 0;)
+	{
+	  ps = pool->solvables + p;
+	  if (!allowarchchange && s->arch != ps->arch && policy_illegal_archchange(solv, s, ps))
+	    continue;
+	  if (!allowvendorchange && s->vendor != ps->vendor && policy_illegal_vendorchange(solv, s, ps))
+	    continue;
+	  queue_push(qs, p);
+	}
+    }
+}
+
+const char *
+policy_illegal2str(Solver *solv, int illegal, Solvable *s, Solvable *rs)
+{
+  Pool *pool = solv->pool;
+  const char *str;
+  if (illegal == POLICY_ILLEGAL_DOWNGRADE)
+    {
+      str = pool_tmpjoin(pool, "downgrade of ", pool_solvable2str(pool, s), 0);
+      return pool_tmpappend(pool, str, " to ", pool_solvable2str(pool, rs));
+    }
+  if (illegal == POLICY_ILLEGAL_NAMECHANGE)
+    {
+      str = pool_tmpjoin(pool, "name change of ", pool_solvable2str(pool, s), 0);
+      return pool_tmpappend(pool, str, " to ", pool_solvable2str(pool, rs));
+    }
+  if (illegal == POLICY_ILLEGAL_ARCHCHANGE)
+    {
+      str = pool_tmpjoin(pool, "architecture change of ", pool_solvable2str(pool, s), 0);
+      return pool_tmpappend(pool, str, " to ", pool_solvable2str(pool, rs));
+    }
+  if (illegal == POLICY_ILLEGAL_VENDORCHANGE)
+    {
+      str = pool_tmpjoin(pool, "vendor change from '", pool_id2str(pool, s->vendor), "' (");
+      if (rs->vendor)
+	{
+          str = pool_tmpappend(pool, str, pool_solvable2str(pool, s), ") to '");
+          str = pool_tmpappend(pool, str, pool_id2str(pool, rs->vendor), "' (");
+	}
+      else
+        str = pool_tmpappend(pool, str, pool_solvable2str(pool, s), ") to no vendor (");
+      return pool_tmpappend(pool, str, pool_solvable2str(pool, rs), ")");
+    }
+  return "unknown illegal change";
+}
+