MDEV-8693 Tests connect.bin connect.endian fail on armhf (on Debian build system)

Author: Alexander Barkov

storage/connect/tabfix.cpp

@@ -511,29 +511,29 @@ void BINCOL::ReadColumn(PGLOBAL g)
   switch (Fmt) {
     case 'X':                 // Standard not converted values
       if (Eds && IsTypeChar(Buf_Type))
-        Value->SetValue(*(longlong*)p);
+        Value->SetValueNonAligned<longlong>(p);
       else
         Value->SetBinValue(p);
 
       break;
     case 'S':                 // Short integer
-      Value->SetValue(*(short*)p);
+      Value->SetValueNonAligned<short>(p);
       break;
     case 'T':                 // Tiny integer
       Value->SetValue(*p);
       break;
     case 'I':                 // Integer
-      Value->SetValue(*(int*)p);
+      Value->SetValueNonAligned<int>(p);
       break;
     case 'G':                 // Large (great) integer
-      Value->SetValue(*(longlong*)p);
+      Value->SetValueNonAligned<longlong>(p);
       break;
     case 'F':                 // Float
     case 'R':                 // Real
-      Value->SetValue((double)*(float*)p);
+      Value->SetValueNonAligned<float>(p);
       break;
     case 'D':                 // Double
-      Value->SetValue(*(double*)p);
+      Value->SetValueNonAligned<double>(p);
       break;
     case 'C':                 // Text
       if (Value->SetValue_char(p, Long)) {

storage/connect/value.h

@@ -116,6 +116,26 @@ class DllExport VALUE : public BLOCK {
   virtual bool   Compute(PGLOBAL g, PVAL *vp, int np, OPVAL op);
   virtual bool   FormatValue(PVAL vp, char *fmt) = 0;
 
+  /**
+    Set value from a non-aligned in-memory value in the machine byte order.
+    TYPE can be either of:
+    - int, short, longlong
+    - uint, ushort, ulonglong
+    - float, double
+    @param - a pointer to a non-aligned value of type TYPE.
+  */
+  template<typename TYPE>
+  void SetValueNonAligned(const char *p)
+  {
+#if defined(__i386__) || defined(__x86_64__)
+    SetValue(*((TYPE*) p)); // x86 can cast non-aligned memory directly
+#else
+    TYPE tmp;               // a slower version for non-x86 platforms
+    memcpy(&tmp, p, sizeof(tmp));
+    SetValue(tmp);
+#endif
+  }
+
  protected:
   virtual bool   SetConstFormat(PGLOBAL, FORMAT&) = 0;
   const   char  *GetXfmt(void);