TUT: fix mesh/parallel/cavity for Alltest mode

- use foamListTimes instead of hard-coded time to track the
  redistribution point. Still slightly fragile...

tutorials/mesh/parallel/cavity/Allrun

@@ -25,16 +25,27 @@ runParallel -s random icoFoam $fileHandler
 # Pick up last result
 cp system/controlDict-latestTime system/controlDict
 
-# Redistribute to 5 processors. Note that new processors only get written
-# a mesh to the current time (0.505). Use -overwrite instead to write the
-# mesh to constant.
+# Redistribute to 5 processors.
+# Note that new processors only get written with a mesh at the current time.
+# Use -overwrite instead to write the mesh to constant
 runParallel -s 5 $decompDict5 redistributePar -cellDist $fileHandler
 
+latestTime=$(foamListTimes -processor -latestTime)
+
+echo "New mesh distribution. Time = $latestTime"
+
 # Run a bit more
 runParallel -s 5 $decompDict5 icoFoam $fileHandler
 
-# Reconstruct mesh and results. Note the time argument to make sure we
-# only pick up the new decomposition
-runParallel -s reconstruct -np 5 redistributePar -reconstruct -time 0.505: $fileHandler
+# Reconstruct mesh and results.
+# The time argument to make sure we only pick up the new decomposition
+if [ -n "$latestTime" ]
+then
+    runParallel -s reconstruct -np 5 redistributePar -reconstruct \
+        -time "${latestTime}:" $fileHandler
+else
+    runParallel -s reconstruct -np 5 redistributePar -reconstruct \
+        -latestTime $fileHandler
+fi
 
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