0032495: Coding rules - eliminate CLang UndefinedBehaviorSanitizer warnings

- fixed CLang UndefinedBehaviorSanitizer warnings

diff --git a/src/AdvApp2Var/AdvApp2Var_ApproxF2var.cxx b/src/AdvApp2Var/AdvApp2Var_ApproxF2var.cxx
index c8595771a88c36d9a1fae7c20d47f8095115d1bf..86f8b910def12792fe97c97dad79f2cddc4dd377 100644 (file)
--- a/src/AdvApp2Var/AdvApp2Var_ApproxF2var.cxx
+++ b/src/AdvApp2Var/AdvApp2Var_ApproxF2var.cxx
@@ -3316,10 +3316,11 @@ int AdvApp2Var_ApproxF2var::mma2cdi_( integer *ndimen,
     integer ilong;
     intptr_t iofwr;
     doublereal* wrkar = 0;
+    doublereal* wrkar_off;
     integer iszwr;
     integer ibb, ier = 0;
     integer isz1, isz2, isz3, isz4;
-    intptr_t ipt1, ipt2, ipt3, ipt4;
+    intptr_t ipt1, ipt2, ipt3;
 
 
 
@@ -3505,17 +3506,17 @@ int AdvApp2Var_ApproxF2var::mma2cdi_( integer *ndimen,
     if (ier > 0) {
        goto L9013;
     }
-    ipt1 = iofwr;
-    ipt2 = ipt1 + isz1;
-    ipt3 = ipt2 + isz2;
-    ipt4 = ipt3 + isz3;
+    wrkar_off = reinterpret_cast<double*>(iofwr * sizeof(double));
+    ipt1 = isz1;
+    ipt2 = ipt1 + isz2;
+    ipt3 = ipt2 + isz3;
 
     if (*iordru >= 0 && *iordru <= 2) {
 
 /* --- Return 2*(IORDRU+1) coeff of 2*(IORDRU+1) polynoms of Hermite 
 --- */
 
-       AdvApp2Var_ApproxF2var::mma1her_(iordru, &wrkar[ipt1], iercod);
+       AdvApp2Var_ApproxF2var::mma1her_(iordru, wrkar_off, iercod);
        if (*iercod > 0) {
            goto L9100;
        }
@@ -3523,10 +3524,10 @@ int AdvApp2Var_ApproxF2var::mma2cdi_( integer *ndimen,
 /* ---- Subract discretizations of polynoms of constraints 
 ---- */
 
-       mma2cd3_(ndimen, nbpntu, &urootl[1], nbpntv, iordru, &sotbu1[1], &
-               sotbu2[1], &ditbu1[1], &ditbu2[1], &wrkar[ipt3], &wrkar[ipt1],
-                &sosotb[sosotb_offset], &soditb[soditb_offset], &disotb[
-               disotb_offset], &diditb[diditb_offset]);
+       mma2cd3_(ndimen, nbpntu, &urootl[1], nbpntv, iordru, &sotbu1[1],
+               &sotbu2[1], &ditbu1[1], &ditbu2[1], &wrkar_off[ipt2], wrkar_off,
+               &sosotb[sosotb_offset], &soditb[soditb_offset],
+               &disotb[disotb_offset], &diditb[diditb_offset]);
     }
 
     if (*iordrv >= 0 && *iordrv <= 2) {
@@ -3534,7 +3535,7 @@ int AdvApp2Var_ApproxF2var::mma2cdi_( integer *ndimen,
 /* --- Return 2*(IORDRV+1) coeff of 2*(IORDRV+1) polynoms of Hermite 
 --- */
 
-       AdvApp2Var_ApproxF2var::mma1her_(iordrv, &wrkar[ipt2], iercod);
+       AdvApp2Var_ApproxF2var::mma1her_(iordrv, &wrkar_off[ipt1], iercod);
        if (*iercod > 0) {
            goto L9100;
        }
@@ -3542,10 +3543,10 @@ int AdvApp2Var_ApproxF2var::mma2cdi_( integer *ndimen,
 /* ---- Subtract discretisations of polynoms of constraint 
 ---- */
 
-       mma2cd2_(ndimen, nbpntu, nbpntv, &vrootl[1], iordrv, &sotbv1[1], &
-               sotbv2[1], &ditbv1[1], &ditbv2[1], &wrkar[ipt4], &wrkar[ipt2],
-                &sosotb[sosotb_offset], &soditb[soditb_offset], &disotb[
-               disotb_offset], &diditb[diditb_offset]);
+       mma2cd2_(ndimen, nbpntu, nbpntv, &vrootl[1], iordrv, &sotbv1[1],
+               &sotbv2[1], &ditbv1[1], &ditbv2[1], &wrkar_off[ipt3], &wrkar_off[ipt1],
+               &sosotb[sosotb_offset], &soditb[soditb_offset],
+               &disotb[disotb_offset], &diditb[diditb_offset]);
     }
 
 /* --------------- Subtract constraints of corners ---------------- 
@@ -3553,11 +3554,11 @@ int AdvApp2Var_ApproxF2var::mma2cdi_( integer *ndimen,
 
     if (*iordru >= 0 && *iordrv >= 0) {
        mma2cd1_(ndimen, nbpntu, &urootl[1], nbpntv, &vrootl[1], iordru, 
-               iordrv, &contr1[contr1_offset], &contr2[contr2_offset], &
-               contr3[contr3_offset], &contr4[contr4_offset], &wrkar[ipt3], &
-               wrkar[ipt4], &wrkar[ipt1], &wrkar[ipt2], &sosotb[
-               sosotb_offset], &soditb[soditb_offset], &disotb[disotb_offset]
-               , &diditb[diditb_offset]);
+               iordrv, &contr1[contr1_offset], &contr2[contr2_offset],
+               &contr3[contr3_offset], &contr4[contr4_offset], &wrkar_off[ipt2],
+               &wrkar_off[ipt3], wrkar_off, &wrkar_off[ipt1],
+               &sosotb[sosotb_offset], &soditb[soditb_offset],
+               &disotb[disotb_offset], &diditb[diditb_offset]);
     }
     goto L9999;
 
@@ -3630,10 +3631,11 @@ int AdvApp2Var_ApproxF2var::mma2ce1_(integer *numdec,
     logical ldbg;
     intptr_t iofwr;
     doublereal* wrkar = 0;
+    doublereal* wrkar_off;
     integer iszwr;
     integer ier;
     integer isz1, isz2, isz3, isz4, isz5, isz6, isz7;
-    intptr_t ipt1, ipt2, ipt3, ipt4, ipt5, ipt6, ipt7;
+    intptr_t ipt1, ipt2, ipt3, ipt4, ipt5, ipt6;
 
 
 
@@ -3796,25 +3798,25 @@ int AdvApp2Var_ApproxF2var::mma2ce1_(integer *numdec,
     iszwr = isz1 + isz2 + isz3 + isz4 + isz5 + isz6 + isz7;
     AdvApp2Var_SysBase anAdvApp2Var_SysBase;
     anAdvApp2Var_SysBase.mcrrqst_(&c__8, &iszwr, wrkar, &iofwr, &ier);
+    wrkar_off = reinterpret_cast<double*> (iofwr * sizeof(double));
     if (ier > 0) {
        goto L9013;
     }
-    ipt1 = iofwr;
-    ipt2 = ipt1 + isz1;
-    ipt3 = ipt2 + isz2;
-    ipt4 = ipt3 + isz3;
-    ipt5 = ipt4 + isz4;
-    ipt6 = ipt5 + isz5;
-    ipt7 = ipt6 + isz6;
+    ipt1 = isz1;
+    ipt2 = ipt1 + isz2;
+    ipt3 = ipt2 + isz3;
+    ipt4 = ipt3 + isz4;
+    ipt5 = ipt4 + isz5;
+    ipt6 = ipt5 + isz6;
 
 /* ----------------- Return Gauss coefficients of integration ---------------- 
 */
 
-    AdvApp2Var_ApproxF2var::mmapptt_(ndjacu, nbpntu, iordru, &wrkar[ipt1], iercod);
+    AdvApp2Var_ApproxF2var::mmapptt_(ndjacu, nbpntu, iordru, wrkar_off, iercod);
     if (*iercod > 0) {
        goto L9999;
     }
-    AdvApp2Var_ApproxF2var::mmapptt_(ndjacv, nbpntv, iordrv, &wrkar[ipt2], iercod);
+    AdvApp2Var_ApproxF2var::mmapptt_(ndjacv, nbpntv, iordrv, &wrkar_off[ipt1], iercod);
     if (*iercod > 0) {
        goto L9999;
     }
@@ -3822,18 +3824,18 @@ int AdvApp2Var_ApproxF2var::mma2ce1_(integer *numdec,
 /* ------------------- Return max polynoms of  Jacobi ------------ 
 */
 
-    AdvApp2Var_ApproxF2var::mma2jmx_(ndjacu, iordru, &wrkar[ipt5]);
-    AdvApp2Var_ApproxF2var::mma2jmx_(ndjacv, iordrv, &wrkar[ipt6]);
+    AdvApp2Var_ApproxF2var::mma2jmx_(ndjacu, iordru, &wrkar_off[ipt5]);
+    AdvApp2Var_ApproxF2var::mma2jmx_(ndjacv, iordrv, &wrkar_off[ipt5]);
 
 /* ------ Calculate the coefficients and their contribution to the error ---- 
 */
 
     mma2ce2_(numdec, ndimen, nbsesp, &ndimse[1], ndminu, ndminv, ndguli, 
-           ndgvli, ndjacu, ndjacv, iordru, iordrv, nbpntu, nbpntv, &epsapr[1]
-           , &sosotb[sosotb_offset], &disotb[disotb_offset], &soditb[
-           soditb_offset], &diditb[diditb_offset], &wrkar[ipt1], &wrkar[ipt2]
-           , &wrkar[ipt5], &wrkar[ipt6], &wrkar[ipt7], &wrkar[ipt3], &wrkar[
-           ipt4], &patjac[patjac_offset], &errmax[1], &errmoy[1], ndegpu, 
+           ndgvli, ndjacu, ndjacv, iordru, iordrv, nbpntu, nbpntv, &epsapr[1],
+           &sosotb[sosotb_offset], &disotb[disotb_offset], &soditb[soditb_offset],
+           &diditb[diditb_offset], wrkar_off, &wrkar_off[ipt1],
+           &wrkar_off[ipt4], &wrkar_off[ipt5], &wrkar_off[ipt6], &wrkar_off[ipt2],
+           &wrkar_off[ipt3], &patjac[patjac_offset], &errmax[1], &errmoy[1], ndegpu, 
            ndegpv, itydec, iercod);
     if (*iercod > 0) {
        goto L9999;
@@ -6167,6 +6169,7 @@ int AdvApp2Var_ApproxF2var::mma2fnc_(integer *ndimen,
     integer  ideb1, ibid1, ibid2, ncfja, ndgre, ilong, 
            ndwrk;
     doublereal* wrkar = 0;
+    doublereal* wrkar_off;
     integer nupil;
     intptr_t iofwr;
     doublereal uvpav[4]        /* was [2][2] */;
@@ -6177,7 +6180,7 @@ int AdvApp2Var_ApproxF2var::mma2fnc_(integer *ndimen,
   integer ncb1;
     doublereal eps3;
     integer isz1, isz2, isz3, isz4, isz5;
-    intptr_t ipt1, ipt2, ipt3, ipt4, ipt5,iptt, jptt;
+    intptr_t ipt1, ipt2, ipt3, ipt4,iptt, jptt;
 
 /* ********************************************************************** 
 */
@@ -6427,19 +6430,19 @@ int AdvApp2Var_ApproxF2var::mma2fnc_(integer *ndimen,
 
     ndwrk = isz1 + isz2 + isz3 + isz4 + isz5;
     anAdvApp2Var_SysBase.mcrrqst_(&c__8, &ndwrk, wrkar, &iofwr, &ier);
+    wrkar_off = reinterpret_cast<double*>(iofwr * sizeof(double));
     if (ier > 0) {
        goto L9013;    }
 /* --> For the parameters of discretisation (NBROOT+2 extremities). */
-    ipt1 = iofwr;
 /* --> For the points of discretisation FPNTAB(NDIMEN,NBROOT+2), */
 /*    FPNTAB(NBROOT,2*(IORDRE+1)) and for WRKAR of MMAPCMP. */
-    ipt2 = ipt1 + isz1;
+    ipt1 = isz1;
 /* --> For the polynoms of Hermit */
-    ipt3 = ipt2 + isz2;
+    ipt2 = ipt1 + isz2;
 /* --> For the Gauss  coeff of integration. */
-    ipt4 = ipt3 + isz3;
+    ipt3 = ipt2 + isz3;
 /* --> For the curve in Jacobi. */
-    ipt5 = ipt4 + isz4;
+    ipt4 = ipt3 + isz4;
 
 /* ------------------ Initialisation of management of cuts --------- 
 */
@@ -6485,15 +6488,15 @@ L1000:
 
 /* -------------------- Normalization of parameters -------------------- */
 
-    mma1nop_(nbroot, &rootlg[1], uvpav, isofav, &wrkar[ipt1], &ier);
+    mma1nop_(nbroot, &rootlg[1], uvpav, isofav, wrkar_off, &ier);
     if (ier > 0) {
        goto L9100;
     }
 
 /* -------------------- Discretisation of FONCNP ------------------------ */
 
-    mma1fdi_(ndimen, uvpav, foncnp, isofav, tconst, nbroot, &wrkar[ipt1], 
-           iordre, ideriv, &wrkar[ipt2], &somtab[(ncb1 * somtab_dim2 + 1) * 
+    mma1fdi_(ndimen, uvpav, foncnp, isofav, tconst, nbroot, wrkar_off, 
+           iordre, ideriv, &wrkar_off[ipt1], &somtab[(ncb1 * somtab_dim2 + 1) *
            somtab_dim1], &diftab[(ncb1 * diftab_dim2 + 1) * diftab_dim1], &
            contr1[(ncb1 * contr1_dim2 + 1) * contr1_dim1 + 1], &contr2[(ncb1 
            * contr2_dim2 + 1) * contr2_dim1 + 1], iercod);
@@ -6508,7 +6511,7 @@ L1000:
                contr1_dim2 + 1) * contr1_dim1 + 1], &contr2[(ncb1 * 
                contr2_dim2 + 1) * contr2_dim1 + 1], &somtab[(ncb1 * 
                somtab_dim2 + 1) * somtab_dim1], &diftab[(ncb1 * diftab_dim2 
-               + 1) * diftab_dim1], &wrkar[ipt2], &wrkar[ipt3], &ier);
+               + 1) * diftab_dim1], &wrkar_off[ipt1], &wrkar_off[ipt2], &ier);
        if (ier > 0) {
            goto L9100;
        }
@@ -6522,8 +6525,8 @@ L1000:
 */
 
     mma1jak_(ndimen, nbroot, iordre, ndgjac, &somtab[(ncb1 * somtab_dim2 + 1) 
-           * somtab_dim1], &diftab[(ncb1 * diftab_dim2 + 1) * diftab_dim1], &
-           wrkar[ipt4], &wrkar[ipt5], &ier);
+           * somtab_dim1], &diftab[(ncb1 * diftab_dim2 + 1) * diftab_dim1],
+           &wrkar_off[ipt3], &wrkar_off[ipt4], &ier);
     if (ier > 0) {
        goto L9100;
     }
@@ -6538,7 +6541,7 @@ L1000:
     if (*iordre >= 0) {
        mma1cnt_(ndimen, iordre, &contr1[(ncb1 * contr1_dim2 + 1) * 
                contr1_dim1 + 1], &contr2[(ncb1 * contr2_dim2 + 1) * 
-               contr2_dim1 + 1], &wrkar[ipt3], ndgjac, &wrkar[ipt5]);
+               contr2_dim1 + 1], &wrkar_off[ipt2], ndgjac, &wrkar_off[ipt4]);
     }
 
 /* ********************************************************************** 
@@ -6548,8 +6551,8 @@ L1000:
 /* ********************************************************************** 
 */
 
-    mma1fer_(ndimen, nbsesp, &ndimse[1], iordre, ndgjac, &wrkar[ipt5], ncflim,
-            &epsapr[1], &wrkar[ipt2], &errmax[ncb1 * errmax_dim1 + 1], &
+    mma1fer_(ndimen, nbsesp, &ndimse[1], iordre, ndgjac, &wrkar_off[ipt4], ncflim,
+            &epsapr[1], &wrkar_off[ipt1], &errmax[ncb1 * errmax_dim1 + 1], &
            errmoy[ncb1 * errmoy_dim1 + 1], &ncoeff[ncb1], &ier);
     if (ier > 0) {
        goto L9100;
@@ -6577,26 +6580,26 @@ L1000:
        AdvApp2Var_MathBase::mmapcmp_((integer*)ndimen, 
                                      &ncfja, 
                                      &ncoeff[ncb1], 
-                                     &wrkar[ipt5], 
-                                     &wrkar[ipt2]);
+                                     &wrkar_off[ipt4],
+                                     &wrkar_off[ipt1]);
        /*pkv t*/
        ilong = *ndimen * *ncflim;
-       AdvApp2Var_SysBase::mvriraz_(&ilong, &wrkar[ipt5]);
+       AdvApp2Var_SysBase::mvriraz_(&ilong, &wrkar_off[ipt4]);
 /* -> Passage to canonic base (-1,1) (result in WRKAR(IPT5)). 
 */
        ndgre = ncoeff[ncb1] - 1;
        i__1 = *ndimen;
        for (nd = 1; nd <= i__1; ++nd) {
-           iptt = ipt2 + ((nd - 1) << 1) * (ndgre / 2 + 1);
-           jptt = ipt5 + (nd - 1) * ncoeff[ncb1];
-           AdvApp2Var_MathBase::mmjacan_(iordre, &ndgre, &wrkar[iptt], &wrkar[jptt]);
+           iptt = ipt1 + ((nd - 1) << 1) * (ndgre / 2 + 1);
+           jptt = ipt4 + (nd - 1) * ncoeff[ncb1];
+           AdvApp2Var_MathBase::mmjacan_(iordre, &ndgre, &wrkar_off[iptt], &wrkar_off[jptt]);
 /* L400: */
        }
 
 /* -> Store the calculated curve */
        ibid1 = 1;
-       AdvApp2Var_MathBase::mmfmca8_(&ncoeff[ncb1], ndimen, &ibid1, ncflim, ndimen, &ibid1, &
-               wrkar[ipt5], &courbe[(ncb1 * courbe_dim2 + 1) * courbe_dim1 + 
+       AdvApp2Var_MathBase::mmfmca8_(&ncoeff[ncb1], ndimen, &ibid1, ncflim, ndimen, &ibid1,
+               &wrkar_off[ipt4], &courbe[(ncb1 * courbe_dim2 + 1) * courbe_dim1 +
                1]);
 
 /* -> Before normalization of constraints on (-1,1), recalculate */

diff --git a/src/AdvApp2Var/AdvApp2Var_SysBase.cxx b/src/AdvApp2Var/AdvApp2Var_SysBase.cxx
index ec648a0779ade994e9e29f5795bfa589253d0b82..6d6a283453d4687f234a8f3f2580691834eb7f2b 100644 (file)
--- a/src/AdvApp2Var/AdvApp2Var_SysBase.cxx
+++ b/src/AdvApp2Var/AdvApp2Var_SysBase.cxx
@@ -115,11 +115,6 @@ int mcrgetv_(integer *sz,
             intptr_t *iad,
             integer *ier);
 
-static
-int mcrlocv_(void* t,
-            intptr_t *l);
-
-
 static struct {
     integer lec, imp, keyb, mae, jscrn, itblt, ibb;
 } mblank__;
@@ -383,9 +378,6 @@ int AdvApp2Var_SysBase::macrchk_()
   
   /* Local variables */
   integer  i__, j;
-  intptr_t ioff;
-  doublereal* t = 0;
-  intptr_t loc;
   
 /* ***********************************************************************
  */
@@ -469,8 +461,6 @@ int AdvApp2Var_SysBase::macrchk_()
 /* ----------------------------------------------------------------------*
  */
 
-/* CALCULATE ADDRESS OF T */
-  mcrlocv_(t, &loc);  
   /* CONTROL OF FLAGS IN THE TABLE */
   i__1 = mcrgene_.ncore;
   for (i__ = 0; i__ < i__1; ++i__) {
@@ -481,10 +471,9 @@ int AdvApp2Var_SysBase::macrchk_()
       intptr_t* pp = p + j;
       if (*pp != -1) {
        
-       ioff = (*pp - loc) / 8;
-       
-       if (t[ioff] != -134744073.) {
-         
+       double* t = reinterpret_cast<double*>(*pp);
+       if (*t != -134744073.)
+       {
          /* MSG : '*** ERREUR  : REMOVAL FROM MEMORY OF ADDRESS
             E:',ICORE(J,I) */
          /*       AND OF RANK ICORE(12,I) */
@@ -727,10 +716,7 @@ int macrgfl_(intptr_t *iadfld,
   
   char cbid[1] = {};
   integer ibid, ienr;
-  doublereal* t = 0;
   integer novfl = 0;
-  intptr_t ioff,iadt;
-  
   
   /* ***********************************************************************
    */
@@ -824,27 +810,25 @@ int macrgfl_(intptr_t *iadfld,
     ifois = 1;
   }
   
-  /*  CALCULATE THE ADDRESS OF T */
-  mcrlocv_(t, &iadt);
-  
+ 
   /* CALCULATE THE OFFSET */
-  ioff = (*iadfld - iadt) / 8;
+  double* t = reinterpret_cast<double*>(*iadfld);
   
   /*  SET TO OVERFLOW OF THE USER ZONE IN CASE OF PRODUCTION VERSION */
   if (*iphase == 1 && novfl == 0) {
     ienr = *iznuti / 8;
-    maoverf_(&ienr, &t[ioff + 1]);
+    maoverf_(&ienr, &t[1]);
   }
     
   /*  UPDATE THE START FLAG */
-  t[ioff] = -134744073.;
+  *t = -134744073.;
   
   /*  FAKE CALL TO STOP THE DEBUGGER : */
   macrbrk_();
   
   /*  UPDATE THE START FLAG */
-  ioff = (*iadflf - iadt) / 8;
-  t[ioff] = -134744073.;
+  t = reinterpret_cast<double*>(*iadflf);
+  *t = -134744073.;
     
   /*  FAKE CALL TO STOP THE DEBUGGER : */
   macrbrk_();
@@ -2076,7 +2060,7 @@ int mcrcomm_(integer *kop,
        itab[(i__ << 2) - 4] = *noct / 8 + 1;
        itab[(i__ << 2) - 3] = ipre;
        itab[(i__ << 2) - 2] = *noct;
-       mcrlocv_(&dtab[ipre - 1], iadr);
+       *iadr = reinterpret_cast<intptr_t> (&dtab[ipre - 1]);
        itab[(i__ << 2) - 1] = *iadr;
        goto L9900;
       }
@@ -2270,7 +2254,7 @@ int AdvApp2Var_SysBase::mcrdelt_(integer *iunit,
 /* SEARCH IN MCRGENE */
 
     n = -1;
-    mcrlocv_(t, &loc);
+    loc = reinterpret_cast<intptr_t> (t);
 
     for (i__ = mcrgene_.ncore - 1; i__ >= 0; --i__) {
        if (*iunit == mcrgene_.icore[i__].unit && *isize == 
@@ -2670,19 +2654,6 @@ int AdvApp2Var_SysBase::mcrlist_(integer *ier) const
  return 0 ;
 } /* mcrlist_ */
 
-
-//=======================================================================
-//function : mcrlocv_
-//purpose  : 
-//=======================================================================
-int mcrlocv_(void* t,
-            intptr_t *l)
-
-{
-  *l = reinterpret_cast<intptr_t> (t);
-  return 0 ;
-}
-
 //=======================================================================
 //function : AdvApp2Var_SysBase::mcrrqst_
 //purpose  : 
@@ -2888,7 +2859,7 @@ int AdvApp2Var_SysBase::mcrrqst_(integer *iunit,
 /*     . add delta for alinement with the base */
 /*     . round to multiple of 8 above */
 
-  mcrlocv_(t, &loc);
+  loc = reinterpret_cast<intptr_t> (t);
     izu = ibyte + loc % *iunit;
     irest = izu % 8;
     if (irest != 0) {

diff --git a/src/NCollection/NCollection_Array1.hxx b/src/NCollection/NCollection_Array1.hxx
index ce020eb0351515467d4ad19430e36bae34775ee2..97718aedb26fc58af39766b253895c686027cc96 100644 (file)
--- a/src/NCollection/NCollection_Array1.hxx
+++ b/src/NCollection/NCollection_Array1.hxx
@@ -390,11 +390,10 @@ public:
                const Standard_Boolean theToCopyData)
   {
     Standard_RangeError_Raise_if (theUpper < theLower, "NCollection_Array1::Resize");
-    const Standard_Integer anOldLen   = Length();
-    const Standard_Integer aNewLen    = theUpper - theLower + 1;
-    const Standard_Integer aLowerOld  = myLowerBound;
+    const Standard_Integer anOldLen = Length();
+    const Standard_Integer aNewLen  = theUpper - theLower + 1;
 
-    TheItemType* aBeginOld = &myData[aLowerOld];
+    TheItemType* aBeginOld = myData != NULL ? &myData[myLowerBound] : NULL;
     myLowerBound = theLower;
     myUpperBound = theUpper;
     if (aNewLen == anOldLen)