Better handling of unexpected plugin behaviors

src/branchrule.rs

@@ -60,27 +60,6 @@ mod tests {
     use crate::Solving;
     use crate::{model::Model, status::Status};
 
-    struct PanickingBranchingRule;
-    impl BranchRule for PanickingBranchingRule {
-        fn execute(&mut self, _candidates: Vec<BranchingCandidate>) -> BranchingResult {
-            panic!("Not implemented")
-        }
-    }
-
-    #[test]
-    #[should_panic]
-    fn panicking_branchrule() {
-        let br = PanickingBranchingRule {};
-
-        Model::new()
-            .hide_output()
-            .include_default_plugins()
-            .read_prob("data/test/gen-ip054.mps")
-            .unwrap()
-            .include_branch_rule("", "", 100000, 1000, 1., Box::new(br))
-            .solve();
-    }
-
     struct FirstChoosingBranchingRule {
         pub chosen: Option<BranchingCandidate>,
     }

src/pricer.rs

@@ -53,30 +53,6 @@ mod tests {
         ProblemOrSolving, Solving,
     };
 
-    struct PanickingPricer;
-
-    impl Pricer for PanickingPricer {
-        fn generate_columns(&mut self, _farkas: bool) -> PricerResult {
-            panic!("Not implemented")
-        }
-    }
-
-    #[test]
-    #[should_panic]
-    fn panicking_pricer() {
-        let pricer = PanickingPricer {};
-
-        let model = crate::model::Model::new()
-            .hide_output()
-            .include_default_plugins()
-            .read_prob("data/test/simple.lp")
-            .unwrap()
-            .include_pricer("", "", 9999999, false, Box::new(pricer));
-
-        // solve model
-        model.solve();
-    }
-
     struct LyingPricer;
 
     impl Pricer for LyingPricer {

src/scip.rs

@@ -741,7 +741,9 @@ impl ScipPtr {
 
             if pricing_res.state == PricerResultState::FoundColumns {
                 let n_vars_after = unsafe { ffi::SCIPgetNVars(scip) };
-                assert!(n_vars_before < n_vars_after);
+                if n_vars_before >= n_vars_after {
+                    return Retcode::Error.into();
+                }
             }
 
             unsafe { *result = pricing_res.state.into() };
@@ -845,10 +847,11 @@ impl ScipPtr {
                 if new_n_sols <= current_n_sols {
                     let heur_name =
                         unsafe { CStr::from_ptr(ffi::SCIPheurGetName(heur)).to_str().unwrap() };
-                    panic!(
+                    eprintln!(
                         "Heuristic {} returned result {:?}, but no solutions were added",
                         heur_name, heur_res
                     );
+                    return Retcode::Error.into();
                 }
             }