make solver_describe_decision always return a rule, add solver_rule2solvable()

that way users of describe_decision have the correct rule, they can use
solver_rule2solvable to get the id of the solvable.

4 files changed, 15 insertions, 17 deletions

diff --git a/src/libsolv.ver b/src/libsolv.ver
index 7982dbb..eec2018 100644
--- a/src/libsolv.ver
+++ b/src/libsolv.ver
@@ -350,6 +350,7 @@ SOLV_1.0 {
 		solver_problemruleinfo2str;
 		solver_rule2job;
 		solver_rule2jobidx;
+		solver_rule2solvable;
 		solver_ruleclass;
 		solver_ruleinfo;
 		solver_ruleliterals;
diff --git a/src/rules.c b/src/rules.c
index ae14eba..677807c 100644
--- a/src/rules.c
+++ b/src/rules.c
@@ -2307,6 +2307,16 @@ solver_rule2job(Solver *solv, Id rid, Id *whatp)
   return solv->job.elements[idx];
 }
 
+Id
+solver_rule2solvable(Solver *solv, Id rid)
+{
+  if (rid >= solv->updaterules && rid < solv->updaterules_end)
+    return rid - solv->updaterules;
+  if (rid >= solv->featurerules && rid < solv->featurerules_end)
+    return rid - solv->featurerules;
+  return 0;
+}
+
 /* check if the newest versions of pi still provides the dependency we're looking for */
 static int
 solver_choicerulecheck(Solver *solv, Id pi, Rule *r, Map *m)
diff --git a/src/rules.h b/src/rules.h
index 9205b86..42e8285 100644
--- a/src/rules.h
+++ b/src/rules.h
@@ -138,6 +138,7 @@ extern SolverRuleinfo solver_ruleclass(struct _Solver *solv, Id rid);
 extern void solver_ruleliterals(struct _Solver *solv, Id rid, Queue *q);
 extern int  solver_rule2jobidx(struct _Solver *solv, Id rid);
 extern Id   solver_rule2job(struct _Solver *solv, Id rid, Id *whatp);
+extern Id   solver_rule2solvable(struct _Solver *solv, Id rid);
 
 
 #ifdef __cplusplus
diff --git a/src/solver.c b/src/solver.c
index a846477..eb4afde 100644
--- a/src/solver.c
+++ b/src/solver.c
@@ -4025,11 +4025,7 @@ solver_describe_decision(Solver *solv, Id p, Id *infop)
   if (i < solv->decisioncnt_update)
     {
       if (i == 0)
-	{
-	  if (infop)
-	    *infop = SYSTEMSOLVABLE;
-	  return SOLVER_REASON_KEEP_INSTALLED;
-	}
+	return SOLVER_REASON_KEEP_INSTALLED;
       if (infop)
 	*infop = why;
       return SOLVER_REASON_RESOLVE_JOB;
@@ -4039,12 +4035,7 @@ solver_describe_decision(Solver *solv, Id p, Id *infop)
       if (why == 0 && pp < 0)
 	return SOLVER_REASON_CLEANDEPS_ERASE;
       if (infop)
-	{
-	  if (why >= solv->updaterules && why < solv->updaterules_end)
-	    *infop = why - solv->updaterules;
-	  else if (why >= solv->featurerules && why < solv->featurerules_end)
-	    *infop = why - solv->featurerules;
-	}
+	*infop = why;
       return SOLVER_REASON_UPDATE_INSTALLED;
     }
   if (i < solv->decisioncnt_resolve)
@@ -4052,12 +4043,7 @@ solver_describe_decision(Solver *solv, Id p, Id *infop)
       if (why == 0 && pp < 0)
 	return SOLVER_REASON_CLEANDEPS_ERASE;
       if (infop)
-	{
-	  if (why >= solv->updaterules && why < solv->updaterules_end)
-	    *infop = why - solv->updaterules;
-	  else if (why >= solv->featurerules && why < solv->featurerules_end)
-	    *infop = why - solv->featurerules;
-	}
+	*infop = why;
       return SOLVER_REASON_KEEP_INSTALLED;
     }
   if (i < solv->decisioncnt_weak)