Comment # 3 on bug 1106843 from Dr. Werner Fink

 #2  0x000055555555885f in write_java_msgstr (stream=0x55555556fa60,
mp=0x55555557a630) at write-java.c:457
 457             abort ();
 (gdb) list
 452           fprintf (stream, " }");
 453         }
 454       else
 455         {
 456           if (mp->msgstr_len != strlen (mp->msgstr) + 1)
 457             abort ();
 458
 459           write_java_string (stream, mp->msgstr);
 460         }
 461     }
 (gdb) print mp->msgstr
 $1 = 0x55555556f810 "Project-Id-Version: \nReport-Msgid-Bugs-To:
\nLanguage:de\nMIME-Version: 1.0\nContent-Type: text/plain;
charset=UTF-8\nContent-Transfer- Encoding: 8bit\n"
 (gdb) print mp->msgstr_len
 $2 = 189

... Indeed the lenght of the message with and without POT-Creation-Date: line
differ!

 echo -ne "Project-Id-Version: \nReport-Msgid-Bugs-To: \nPOT-Creation-Date:
2018-08-30 16:51+0200\nLanguage: de\nMIME-Version: 1.0\nContent-Type:
text/plain; charset=UTF-8\nContent-Transfer-Encoding: 8bit\n" | wc -c
 188

 echo -ne "Project-Id-Version: \nReport-Msgid-Bugs-To: \nLanguage:
de\nMIME-Version: 1.0\nContent-Type: text/plain;
charset=UTF-8\nContent-Transfer-Encoding: 8bit\n" | wc -c
 147