STYLE: avoid potential deadlock when resizing from zero-sized list

- not yet triggered by any code, but avoid anyhow

src/OpenFOAM/containers/Lists/List/ListI.H

@@ -163,6 +163,8 @@ inline T& Foam::List<T>::newElmt(const label i)
 
     if (i >= n)
     {
+        if (!n) n = 1;  // Avoid dead-lock when starting from zero-sized
+
         do
         {
             n *= 2;

src/OpenFOAM/db/IOstreams/Tstreams/ITstream.C

@@ -114,8 +114,10 @@ void Foam::ITstream::reserveCapacity
 
         label n = tokenList::size();
 
-        if (nElem >= n)
+        if (nElem > n)
         {
+            if (!n) n = 1;  // Avoid dead-lock when starting from zero-sized
+
             do
             {
                 n *= 2;