fix some issues flagged by coverity scan

src/MISC/fix_imd.cpp

@@ -581,9 +581,8 @@ FixIMD::FixIMD(LAMMPS *lmp, int narg, char **arg) :
       msglen += 3*4*num_coords+IMDHEADERSIZE;
     }
     msgdata = new char[msglen];
-  }
-  else {
-    msglen = 3*sizeof(float)*num_coords+IMDHEADERSIZE;
+  } else {
+    msglen = 3*(int)sizeof(float)*num_coords+IMDHEADERSIZE;
     msgdata = new char[msglen];
   }
 

src/SHOCK/fix_append_atoms.cpp

@@ -49,7 +49,6 @@ FixAppendAtoms::FixAppendAtoms(LAMMPS *lmp, int narg, char **arg) :
 
   scaleflag = 1;
   spatflag=0;
-  spatialid = nullptr;
   size = 0.0;
   xloflag = xhiflag = yloflag = yhiflag = zloflag = zhiflag = 0;
 
@@ -60,9 +59,6 @@ FixAppendAtoms::FixAppendAtoms(LAMMPS *lmp, int narg, char **arg) :
   rany = 0.0;
   ranz = 0.0;
 
-  randomx = nullptr;
-  randomt = nullptr;
-
   if (domain->lattice->nbasis == 0)
     error->all(FLERR,"Fix append/atoms requires a lattice be defined");
 
@@ -123,6 +119,7 @@ FixAppendAtoms::FixAppendAtoms(LAMMPS *lmp, int narg, char **arg) :
       if (strcmp(arg[iarg+1],"f_") == 0)
         error->all(FLERR, "Bad fix ID in fix append/atoms command");
       spatflag = 1;
+      delete[] spatialid;
       spatialid = utils::strdup(arg[iarg+1]+2);
       spatlead = utils::numeric(FLERR,arg[iarg+2],false,lmp);
       iarg += 3;
@@ -152,6 +149,7 @@ FixAppendAtoms::FixAppendAtoms(LAMMPS *lmp, int narg, char **arg) :
       ranz = utils::numeric(FLERR,arg[iarg+3],false,lmp);
       xseed = utils::inumeric(FLERR,arg[iarg+4],false,lmp);
       if (xseed <= 0) error->all(FLERR,"Illegal fix append/atoms command");
+      delete randomx;
       randomx = new RanMars(lmp,xseed + comm->me);
       iarg += 5;
     } else if (strcmp(arg[iarg],"temp") == 0) {
@@ -165,7 +163,10 @@ FixAppendAtoms::FixAppendAtoms(LAMMPS *lmp, int narg, char **arg) :
       if (t_period <= 0) error->all(FLERR,"Illegal fix append/atoms command");
       if (t_extent <= 0) error->all(FLERR,"Illegal fix append/atoms command");
       if (tseed <= 0) error->all(FLERR,"Illegal fix append/atoms command");
+      delete randomt;
       randomt = new RanMars(lmp,tseed + comm->me);
+      delete[] gfactor1;
+      delete[] gfactor2;
       gfactor1 = new double[atom->ntypes+1];
       gfactor2 = new double[atom->ntypes+1];
       iarg += 5;

src/VORONOI/compute_voronoi_atom.cpp

@@ -55,16 +55,10 @@ ComputeVoronoi::ComputeVoronoi(LAMMPS *lmp, int narg, char **arg) :
   surface = VOROSURF_NONE;
   maxedge = 0;
   fthresh = ethresh = 0.0;
-  radstr = nullptr;
   onlyGroup = false;
   occupation = false;
 
-  con_mono = nullptr;
-  con_poly = nullptr;
-  tags = nullptr;
   oldmaxtag = 0;
-  occvec = sendocc = lroot = lnext = nullptr;
-  faces = nullptr;
 
   int iarg = 3;
   while (iarg<narg) {
@@ -79,6 +73,7 @@ ComputeVoronoi::ComputeVoronoi(LAMMPS *lmp, int narg, char **arg) :
     else if (strcmp(arg[iarg], "radius") == 0) {
       if (iarg + 2 > narg || strstr(arg[iarg+1],"v_") != arg[iarg+1] )
         error->all(FLERR,"Illegal compute voronoi/atom command");
+      delete[] radstr;
       radstr = utils::strdup(&arg[iarg+1][2]);
       iarg += 2;
     }

src/respa.cpp

@@ -125,6 +125,8 @@ Respa::Respa(LAMMPS *lmp, int narg, char **arg) :
       nhybrid_styles = hybrid->nstyles;
       // each hybrid sub-style needs to be assigned to a respa level
       if (iarg + nhybrid_styles > narg) error->all(FLERR, "Illegal run_style respa command");
+      delete[] hybrid_level;
+      delete[] hybrid_compute;
       hybrid_level = new int[nhybrid_styles];
       hybrid_compute = new int[nhybrid_styles];
       for (int i = 0; i < nhybrid_styles; ++i) {