Fix possibly invalid pointer

src/mmg2d/analys_2d.c

@@ -54,6 +54,10 @@ int MMG2D_setadj(MMG5_pMesh mesh, int8_t init_cc) {
   int16_t          tag;
   int8_t           i,ii,i1,i2;
 
+  if ( !mesh->nt ) {
+    return 1;
+  }
+
   if ( abs(mesh->info.imprim) > 5  || mesh->info.ddebug )
     fprintf(stdout,"  ** SETTING TOPOLOGY\n");
 

src/mmg2d/hash_2d.c

@@ -29,7 +29,7 @@
  * \param mesh pointer toward the mesh
  * \return 1 if success, 0 if fail
  *
- * Create adjacency relations between the triangles dein the mesh
+ * Create adjacency relations between the triangles in the mesh
  *
  */
 int MMG2D_hashTria(MMG5_pMesh mesh) {
@@ -40,7 +40,7 @@ int MMG2D_hashTria(MMG5_pMesh mesh) {
   unsigned int   key;
 
   if ( mesh->adja )  return 1;
-  if ( !mesh->nt )  return 0;
+  if ( !mesh->nt )  return 1;
 
   /* memory alloc */
   MMG5_SAFE_CALLOC(hcode,mesh->nt+1,MMG5_int,return 0);

src/mmg2d/length_2d.c

@@ -140,6 +140,10 @@ int MMG2D_prilen(MMG5_pMesh mesh,MMG5_pSol sol) {
   ibmax = 0;
   nullEdge = 0;
 
+  if ( !mesh->nt ) {
+    return 0;
+  }
+
   for (k=0; k<9; k++)  hl[k] = 0;
 
   for (k=1; k<=mesh->nt; k++) {

src/mmg2d/quality_2d.c

@@ -187,6 +187,10 @@ int MMG2D_outqua(MMG5_pMesh mesh,MMG5_pSol met) {
   MMG5_int      k,iel,ok,nex;
   static int8_t mmgWarn0;
 
+  if ( !mesh->nt ) {
+    return 1;
+  }
+
   /* Compute triangle quality*/
   for (k=1; k<=mesh->nt; k++) {
     pt = &mesh->tria[k];

src/mmg2d/zaldy_2d.c

@@ -64,7 +64,9 @@ void MMG2D_delPt(MMG5_pMesh mesh,MMG5_int ip) {
   ppt->tmp    = mesh->npnil;
 
   mesh->npnil = ip;
-  if ( ip == mesh->np )  mesh->np--;
+  if ( ip == mesh->np ) {
+    while ( (!MG_VOK((&mesh->point[mesh->np]))) && mesh->np )  mesh->np--;
+  }
 }
 
 void MMG5_delEdge(MMG5_pMesh mesh,MMG5_int iel) {
@@ -119,7 +121,9 @@ int MMG2D_delElt(MMG5_pMesh mesh,MMG5_int iel) {
     memset(&mesh->adja[iadr],0,3*sizeof(MMG5_int));
 
   mesh->nenil = iel;
-  if ( iel == mesh->nt )  mesh->nt--;
+  if ( iel == mesh->nt ) {
+    while ( (!MG_EOK((&mesh->tria[mesh->nt]))) && mesh->nt ) mesh->nt--;
+  }
   return 1;
 }
 

src/mmg3d/anisomovpt_3d.c

@@ -328,6 +328,9 @@ int MMG5_movbdyregpt_ani(MMG5_pMesh mesh, MMG5_pSol met, MMG3D_pPROctree PROctre
 
   /** Step 5 : come back to original problem, compute patch in triangle iel and
    * check that geometric approx has not been degraded too much */
+  // Remark: if we call following function with a pointer for n, we have to set
+  // the pointer again after the function call as it may invalidate it if it
+  // reallocates the xpoint array
   nxp = MMG3D_movbdyregpt_geom(mesh,lists,kel,ip0,n,lambda,o,no);
   if ( nxp < 0 ) {
     return -1;

src/mmg3d/movpt_3d.c

@@ -478,6 +478,7 @@ int MMG3D_rotate_surfacicBall(MMG5_pMesh mesh,MMG5_int *lists,int ilists,MMG5_in
 * Compute the Bezier patch at element \a lists[kel], compute the new point
 * coordinates, normal and tangent and check the geometric approximation.
 *
+* \warning may invalidate n if it is a pointer toward the xpoint array
 */
 int MMG3D_movbdyregpt_geom(MMG5_pMesh mesh,MMG5_int *lists,const MMG5_int kel,
                            const MMG5_int ip0,double n[3],double lambda[3],double o[3],
@@ -629,7 +630,7 @@ int MMG5_movbdyregpt_iso(MMG5_pMesh mesh, MMG5_pSol met, MMG3D_pPROctree PROctre
   MMG5_pPoint       p0;
   MMG5_Tria         tt;
   MMG5_pxPoint      pxp;
-  double            *n,r[3][3],lispoi[3*MMG3D_LMAX+1],ux,uy,det2d;
+  double            n[3],r[3][3],lispoi[3*MMG3D_LMAX+1],ux,uy,det2d;
   double            detloc,oppt[2],step,lambda[3];
   double            ll,m[2],o[3],no[3];
   double            calold,calnew,caltmp,callist[MMG3D_LMAX+2];
@@ -650,7 +651,11 @@ int MMG5_movbdyregpt_iso(MMG5_pMesh mesh, MMG5_pSol met, MMG3D_pPROctree PROctre
   p0 = &mesh->point[ip0];
   assert( p0->xp && !MG_EDG(p0->tag) );
 
-  n = &(mesh->xpoint[p0->xp].n1[0]);
+  /* Don't use a pointer for n to avoid issues with the reallocation of the
+   * xpoint array and invalid pointers (see ls-CenIn-DisOut-8 test of ParMmg) */
+  n[0] = mesh->xpoint[p0->xp].n1[0];
+  n[1] = mesh->xpoint[p0->xp].n1[1];
+  n[2] = mesh->xpoint[p0->xp].n1[2];
 
   /** Step 1 : rotation matrix that sends normal n to the third coordinate vector of R^3 */
   if ( !MMG5_rotmatrix(n,r) ) return 0;
@@ -727,6 +732,9 @@ int MMG5_movbdyregpt_iso(MMG5_pMesh mesh, MMG5_pSol met, MMG3D_pPROctree PROctre
   lambda[0] = 1.0 - lambda[1] - lambda[2];
 
   /** Step 5 : come back to original problem, and compute patch in triangle iel */
+  // Remark: if we call following function with a pointer for n, we have to set
+  // the pointer again after the function call as it may invalidate it if it
+  // reallocates the xpoint array
   nxp = MMG3D_movbdyregpt_geom(mesh,lists,kel,ip0,n,lambda,o,no);
   if ( nxp < 0 ) {
     return -1;

src/mmg3d/zaldy_3d.c

@@ -91,7 +91,7 @@ void MMG3D_delPt(MMG5_pMesh mesh,MMG5_int ip) {
   ppt->tmp    = mesh->npnil;
   mesh->npnil = ip;
   if ( ip == mesh->np ) {
-    while ( !MG_VOK((&mesh->point[mesh->np])) )  mesh->np--;
+    while ( (!MG_VOK((&mesh->point[mesh->np]))) && mesh->np )  mesh->np--;
   }
 }
 
@@ -135,7 +135,7 @@ int MMG3D_delElt(MMG5_pMesh mesh,MMG5_int iel) {
     memset(&mesh->adja[iadr],0,4*sizeof(MMG5_int));
   mesh->nenil = iel;
   if ( iel == mesh->ne ) {
-    while ( !MG_EOK((&mesh->tetra[mesh->ne])) )  mesh->ne--;
+    while ( (!MG_EOK((&mesh->tetra[mesh->ne]))) && mesh->ne )  mesh->ne--;
   }
   return 1;
 }

src/mmgs/zaldy_s.c

@@ -64,7 +64,7 @@ void MMGS_delPt(MMG5_pMesh mesh,MMG5_int ip) {
   ppt->tmp    = mesh->npnil;
   mesh->npnil = ip;
   if ( ip == mesh->np ) {
-    while ( !MG_VOK((&mesh->point[mesh->np])) )  mesh->np--;
+    while ( (!MG_VOK((&mesh->point[mesh->np]))) && mesh->np )  mesh->np--;
   }
 }
 
@@ -104,7 +104,7 @@ int MMGS_delElt(MMG5_pMesh mesh,MMG5_int iel) {
     memset(&mesh->adja[3*(iel-1)+1],0,3*sizeof(MMG5_int));
   mesh->nenil = iel;
   if ( iel == mesh->nt ) {
-    while ( !MG_EOK((&mesh->tria[mesh->nt])) )  mesh->nt--;
+    while ( (!MG_EOK((&mesh->tria[mesh->nt]))) && mesh->nt )  mesh->nt--;
   }
   return 1;
 }