Merge remote-tracking branch 'origin/v9-minor'

Author: svigerske

CHANGELOG

@@ -350,6 +350,7 @@ Fixed bugs
 - corrected computation of number of variables affected by symmetry
 - fixed computation of symmetry group size
 - correct comparison conditions in checkRedundancySide() of cons_varbound.c to ensure pair redundancy
+- also for the initial LP solve force acceptance of Farkas row in SCIPlpGetDualfarkas() if all other means for obtaining a reliable Farkas proof have failed
 
 Build system
 ------------

check/CMakeLists.txt

@@ -560,6 +560,7 @@ set(pairs_Issue
     "instances/Issue/3911.cip\;-30386.2338470598\;lexdual"
     "instances/Issue/3917.cip\;+infinity\;default"
     "instances/Issue/3920.cip\;0\;presolving_milp_off"
+    "instances/Issue/3932.cip\;+infinity\;reduced_tolerance"
 )
 
 #

check/coverage/settings/reduced_tolerance.set

@@ -0,0 +1,5 @@
+lp/solvefreq = -1
+numerics/sumepsilon = 1e-9
+numerics/feastol = 1e-9
+presolving/maxrounds = 0
+heuristics/trivial/freq = -1

check/coverage/settings/tolerance.set

@@ -1 +1,2 @@
+numerics/sumepsilon = 1e-9
 numerics/feastol = 1e-9

check/instances/Issue/3932.cip

@@ -0,0 +1,15 @@
+STATISTICS
+  Problem name     : t_t_seed
+  Variables        : 3 (0 binary, 1 integer, 0 implicit integer, 2 continuous)
+  Constraints      : 0 initial, 3 maximal
+OBJECTIVE
+  Sense            : minimize
+VARIABLES
+  [integer] <t_t_x0>: obj=0, original bounds=[29,200]
+  [continuous] <t_t_x4>: obj=0, original bounds=[-200,-88]
+  [continuous] <t_t_x2>: obj=0, original bounds=[-200,-51]
+CONSTRAINTS
+  [linear] <_C1>:  +14.66<t_t_x0>[I] +83.96<t_t_x4>[C] -99.73<t_t_x2>[C] <= 4758.33;
+  [linear] <_C3>:  +36.95<t_t_x0>[I] -77.02<t_t_x4>[C] +27.3<t_t_x2>[C] <= 15108.87;
+  [linear] <dualproof_bnd_1>:  +35.3812724355761<t_t_x0>[I] -106.595454727765<t_t_x4>[C] >= 26150.7507972695;
+END

src/scip/solve.c

@@ -1581,6 +1581,7 @@ SCIP_RETCODE solveNodeInitialLP(
    SCIP_EVENTFILTER*     eventfilter,        /**< global event filter */
    SCIP_CLIQUETABLE*     cliquetable,        /**< clique table data structure */
    SCIP_Bool             newinitconss,       /**< do we have to add new initial constraints? */
+   SCIP_Bool             forcedlpsolve,      /**< would SCIP abort if the LP is not solved? */
    SCIP_Bool*            cutoff,             /**< pointer to store whether the node can be cut off */
    SCIP_Bool*            lperror             /**< pointer to store whether an unresolved error in LP solving occured */
    )
@@ -1623,7 +1624,7 @@ SCIP_RETCODE solveNodeInitialLP(
    /* solve initial LP */
    SCIPsetDebugMsg(set, "node: solve initial LP\n");
    SCIP_CALL( SCIPlpSolveAndEval(lp, set, messagehdlr, blkmem, stat, eventqueue, eventfilter, transprob,
-         SCIPnodeGetDepth(SCIPtreeGetFocusNode(tree)) == 0 ? set->lp_rootiterlim : set->lp_iterlim, TRUE, TRUE, FALSE, FALSE, lperror) );
+         SCIPnodeGetDepth(SCIPtreeGetFocusNode(tree)) == 0 ? set->lp_rootiterlim : set->lp_iterlim, TRUE, TRUE, FALSE, forcedlpsolve, lperror) );
    assert(lp->flushed);
    assert(lp->solved || *lperror);
 
@@ -3257,7 +3258,8 @@ SCIP_RETCODE solveNodeLP(
    {
       /* load and solve the initial LP of the node */
       SCIP_CALL( solveNodeInitialLP(blkmem, set, messagehdlr, stat, transprob, origprob, primal, tree, reopt, lp,
-            pricestore, sepastore, cutpool, branchcand, eventqueue, eventfilter, cliquetable, newinitconss, cutoff, lperror) );
+            pricestore, sepastore, cutpool, branchcand, eventqueue, eventfilter, cliquetable, newinitconss,
+            forcedlpsolve, cutoff, lperror) );
 
       assert(*cutoff || *lperror || (lp->flushed && lp->solved));
       SCIPsetDebugMsg(set, "price-and-cut-loop: initial LP status: %d, LP obj: %g\n",