Resolve some compiler warnings

src/equil/vcs_rxnadj.cpp

@@ -379,7 +379,7 @@ int VCS_SOLVE::vcs_rxn_adj_cg()
                 // single species phases will disappear. The sign of DG(I) will
                 // indicate which way the reaction will go. Then, we need to
                 // follow the reaction to see which species will zero out first.
-                size_t k;
+                size_t k = npos;
                 double dss;
                 if (m_deltaGRxn_new[irxn] > 0.0) {
                     dss = m_molNumSpecies_old[kspec];

src/kinetics/Reaction.cpp

@@ -205,7 +205,7 @@ ChemicallyActivatedReaction::ChemicallyActivatedReaction(
         const Composition& reactants_, const Composition& products_,
         const Arrhenius& low_rate_, const Arrhenius& high_rate_,
         const ThirdBody& tbody)
-    : FalloffReaction(reactants_, products_, low_rate, high_rate, tbody)
+    : FalloffReaction(reactants_, products_, low_rate_, high_rate_, tbody)
 {
     reaction_type = CHEMACT_RXN;
 }

src/numerics/RootFind.cpp

@@ -172,7 +172,7 @@ int RootFind::solve(doublereal xmin, doublereal xmax, int itmax, doublereal& fun
     int topBump = 0;
     FILE* fp = 0;
     int doFinalFuncCall = 0;
-    doublereal x1, x2, xnew, f1, f2, fnew, slope;
+    doublereal x1, x2, xnew, f1, f2, fnew, slope = 0;
     doublereal deltaX2 = 0.0, deltaXnew = 0.0;
     int posStraddle = 0;
     int retn = ROOTFIND_FAILEDCONVERGENCE;

src/thermo/RedlichKisterVPSSTP.cpp

@@ -613,7 +613,7 @@ void RedlichKisterVPSSTP::Vint(double& VintOut, double& voltsOut)
 {
     warn_deprecated("RedlichKisterVPSSTP::Vint",
                     "To be removed after Cantera 2.3.");
-    double XA;
+    double XA = 0;
     doublereal T = temperature();
     double Volts = 0.0;
     lnActCoeff_Scaled_.assign(m_kk, 0.0);