Drop padding in blk* when finalizing file

src/main.cpp

@@ -1572,7 +1572,7 @@ bool CBlock::DisconnectBlock(CBlockIndex *pindex, CCoinsViewCache &view, bool *p
     }
 }
 
-void static FlushBlockFile()
+void static FlushBlockFile(bool fFinalize = false)
 {
     LOCK(cs_LastBlockFile);
 
@@ -1580,12 +1580,16 @@ void static FlushBlockFile()
 
     FILE *fileOld = OpenBlockFile(posOld);
     if (fileOld) {
+        if (fFinalize)
+            TruncateFile(fileOld, infoLastBlockFile.nSize);
         FileCommit(fileOld);
         fclose(fileOld);
     }
 
     fileOld = OpenUndoFile(posOld);
     if (fileOld) {
+        if (fFinalize)
+            TruncateFile(fileOld, infoLastBlockFile.nUndoSize);
         FileCommit(fileOld);
         fclose(fileOld);
     }
@@ -1991,7 +1995,7 @@ bool FindBlockPos(CDiskBlockPos &pos, unsigned int nAddSize, unsigned int nHeigh
     } else {
         while (infoLastBlockFile.nSize + nAddSize >= MAX_BLOCKFILE_SIZE) {
             printf("Leaving block file %i: %s\n", nLastBlockFile, infoLastBlockFile.ToString().c_str());
-            FlushBlockFile();
+            FlushBlockFile(true);
             nLastBlockFile++;
             infoLastBlockFile.SetNull();
             pblocktree->ReadBlockFileInfo(nLastBlockFile, infoLastBlockFile); // check whether data for the new file somehow already exist; can fail just fine