Fix MIPS build failure: Handle unaligned buffers in connect's TYPBLK class

On MIPS platforms (and probably others) unaligned memory access results in a
bus error. In the connect storage engine, block data for some data formats is
stored packed in memory and the TYPBLK class is used to read values from it.
Since TYPBLK does not have special handling for this packed memory, it can
quite easily result in unaligned memory accesses.

The simple way to fix this is to perform all accesses to the main buffer
through memcpy. With GCC and optimizations turned on, this call to memcpy is
completely optimized away on architectures where unaligned accesses are ok
(like x86).

Contributors:
James Cowgill <jcowgill@debian.org>

storage/connect/valblk.cpp

@@ -268,14 +268,14 @@ bool TYPBLK<TYPE>::Init(PGLOBAL g, bool check)
 template <class TYPE>
 char *TYPBLK<TYPE>::GetCharString(char *p, int n)
   {
-  sprintf(p, Fmt, Typp[n]);
+  sprintf(p, Fmt, UnalignedRead(n));
   return p;
   } // end of GetCharString
 
 template <>
 char *TYPBLK<double>::GetCharString(char *p, int n)
   {
-  sprintf(p, Fmt, Prec, Typp[n]);
+  sprintf(p, Fmt, Prec, UnalignedRead(n));
   return p;
   } // end of GetCharString
 
@@ -291,7 +291,7 @@ void TYPBLK<TYPE>::SetValue(PVAL valp, int n)
   ChkTyp(valp);
 
   if (!(b = valp->IsNull()))
-    Typp[n] = GetTypedValue(valp);
+    UnalignedWrite(n, GetTypedValue(valp));
   else
     Reset(n);
 
@@ -353,9 +353,9 @@ void TYPBLK<TYPE>::SetValue(PCSZ p, int n)
   ulonglong val = CharToNumber(p, strlen(p), maxval, Unsigned, &minus); 
     
   if (minus && val < maxval)
-    Typp[n] = (TYPE)(-(signed)val);
+    UnalignedWrite(n, (TYPE)(-(signed)val));
   else
-    Typp[n] = (TYPE)val;
+    UnalignedWrite(n, (TYPE)val);
 
   SetNull(n, false);
   } // end of SetValue
@@ -398,7 +398,7 @@ void TYPBLK<double>::SetValue(PCSZ p, int n)
 		throw Type;
 	} // endif Check
 
-  Typp[n] = atof(p);
+  UnalignedWrite(n, atof(p));
   SetNull(n, false);
   } // end of SetValue
 
@@ -430,7 +430,7 @@ void TYPBLK<TYPE>::SetValue(PVBLK pv, int n1, int n2)
   ChkTyp(pv);
 
   if (!(b = pv->IsNull(n2) && Nullable))
-    Typp[n1] = GetTypedValue(pv, n2);
+    UnalignedWrite(n1, GetTypedValue(pv, n2));
   else
     Reset(n1);
 
@@ -481,10 +481,10 @@ void TYPBLK<TYPE>::SetMin(PVAL valp, int n)
   {
   CheckParms(valp, n)
   TYPE  tval = GetTypedValue(valp);
-  TYPE& tmin = Typp[n];
+  TYPE  tmin = UnalignedRead(n);
 
   if (tval < tmin)
-    tmin = tval;
+    UnalignedWrite(n, tval);
 
   } // end of SetMin
 
@@ -496,10 +496,10 @@ void TYPBLK<TYPE>::SetMax(PVAL valp, int n)
   {
   CheckParms(valp, n)
   TYPE  tval = GetTypedValue(valp);
-  TYPE& tmin = Typp[n];
+  TYPE  tmin = UnalignedRead(n);
 
   if (tval > tmin)
-    tmin = tval;
+    UnalignedWrite(n, tval);
 
   } // end of SetMax
 
@@ -513,8 +513,7 @@ void TYPBLK<TYPE>::SetValues(PVBLK pv, int k, int n)
   CheckType(pv)
   TYPE *lp = ((TYPBLK*)pv)->Typp;
 
-  for (int i = k; i < n; i++)          // TODO
-    Typp[i] = lp[i];
+  memcpy(Typp + k, lp + k, sizeof(TYPE) * n);
 
   } // end of SetValues
 #endif // 0
@@ -525,7 +524,7 @@ void TYPBLK<TYPE>::SetValues(PVBLK pv, int k, int n)
 template <class TYPE>
 void TYPBLK<TYPE>::Move(int i, int j)
   {
-  Typp[j] = Typp[i];
+  UnalignedWrite(j, UnalignedRead(i));
   MoveNull(i, j);
   } // end of Move
 
@@ -539,7 +538,7 @@ int TYPBLK<TYPE>::CompVal(PVAL vp, int n)
   ChkIndx(n);
   ChkTyp(vp);
 #endif   // _DEBUG
-  TYPE mlv = Typp[n];
+  TYPE mlv = UnalignedRead(n);
   TYPE vlv = GetTypedValue(vp);
 
   return (vlv > mlv) ? 1 : (vlv < mlv) ? (-1) : 0;
@@ -551,8 +550,8 @@ int TYPBLK<TYPE>::CompVal(PVAL vp, int n)
 template <class TYPE>
 int TYPBLK<TYPE>::CompVal(int i1, int i2)
   {
-  TYPE lv1 = Typp[i1];
-  TYPE lv2 = Typp[i2];
+  TYPE lv1 = UnalignedRead(i1);
+  TYPE lv2 = UnalignedRead(i2);
 
   return (lv1 > lv2) ? 1 : (lv1 < lv2) ? (-1) : 0;
   } // end of CompVal
@@ -589,7 +588,7 @@ int TYPBLK<TYPE>::Find(PVAL vp)
   TYPE n = GetTypedValue(vp);
 
   for (i = 0; i < Nval; i++)
-    if (n == Typp[i])
+    if (n == UnalignedRead(i))
       break;
 
   return (i < Nval) ? i : (-1);
@@ -605,7 +604,7 @@ int TYPBLK<TYPE>::GetMaxLength(void)
   int i, n, m;
 
   for (i = n = 0; i < Nval; i++) {
-    m = sprintf(buf, Fmt, Typp[i]);
+    m = sprintf(buf, Fmt, UnalignedRead(i));
     n = MY_MAX(n, m);
     } // endfor i
 
@@ -1335,7 +1334,7 @@ char *DATBLK::GetCharString(char *p, int n)
   char *vp;
 
   if (Dvalp) {
-    Dvalp->SetValue(Typp[n]);
+    Dvalp->SetValue(UnalignedRead(n));
     vp = Dvalp->GetCharString(p);
   } else
     vp = TYPBLK<int>::GetCharString(p, n);
@@ -1351,7 +1350,7 @@ void DATBLK::SetValue(PCSZ p, int n)
   if (Dvalp) {
     // Decode the string according to format
     Dvalp->SetValue_psz(p);
-    Typp[n] = Dvalp->GetIntValue();
+    UnalignedWrite(n, Dvalp->GetIntValue());
   } else
     TYPBLK<int>::SetValue(p, n);