Execute #@exec earlier to allow #@if to depend on it

If one wants to use code from packages in #@if, one can now load those
packages via #@exec.

lib/test.gi

@@ -87,7 +87,10 @@ InstallGlobalFunction(ParseTestInput, function(str, ignorecomments, fnam)
  if ignorecomments = true then
  # ignore comment lines and empty lines at beginning of file
  Add(ign, i);
- if Length(lines[i]) > 3 and lines[i]{[1..2]} = "#@" then
+ # execute `#@exec` immediately so `#@if` can depend on it
+ if StartsWith(lines[i], "#@exec") then
+ Read(InputTextString(Concatenation(lines[i]{[7..Length(lines[i])]}, ";\n")));
+ elif Length(lines[i]) > 3 and lines[i]{[1..2]} = "#@" then
  Add(commands, lines[i]);
  fi;
  i := i+1;
@@ -347,6 +350,11 @@ end);
 ## reached. If a <C>#@else</C> is present then the code after the <C>#@else</C>
 ## is used if and only if <C>EXPR</C> evaluated to <K>false</K>. Finally,
 ## once <C>#fi</C> is reached, evaluation continues normally.
+## <P/>
+## Note that <C>EXPR</C> is evaluated after all <C>#@exec</C> lines have been
+## executed but before any tests are run. Thus, it cannot depend on test
+## results or packages loaded in tests, but it can depend on packages loaded
+## via <C>#@exec</C>.
 ## </Item>
 ## </List>
 ## By default the actual &GAP; output is compared exactly with the
@@ -648,8 +656,6 @@ InstallGlobalFunction("Test", function(arg)
  else
  opts.localdef := Concatenation(opts.localdef, ", ", line);
  fi;
- elif StartsWith(line, "#@exec") then
- Read(InputTextString(Concatenation(line{[7..Length(line)]}, ";\n")));
  else
  ErrorNoReturn("Invalid #@ test option: ", line);
  fi;