ensure id string doesn't get set to the empty string (bug # 56271)

diff --git a/src/MCview/PDBfile.java b/src/MCview/PDBfile.java
index c671ec2..b368b91 100755 (executable)
--- a/src/MCview/PDBfile.java
+++ b/src/MCview/PDBfile.java
@@ -55,7 +55,7 @@ public class PDBfile extends jalview.io.AlignFile
   public void parse() throws IOException
   {
     // TODO set the filename sensibly
-    id = (inFile == null) ? "PDBFILE" : inFile.getName();
+    id = (inFile == null || inFile.getName()==null || inFile.getName().length()==0) ? "PDBFILE" : inFile.getName();
     try
     {
       chains = new Vector();
@@ -72,10 +72,15 @@ public class PDBfile extends jalview.io.AlignFile
         {
           if (line.length()>62)
           {
+            String tid;
             if (line.length()>67) {
-              id = line.substring(62, 67).trim();
+              tid = line.substring(62, 67).trim();
             } else {
-              id=line.substring(62).trim();
+              tid=line.substring(62).trim();
+            }
+            if (tid.length()>0)
+            {
+              id = tid;
             }
             continue;
           }