HPCC-31416 CDistributedSuperFile::querySubFile may return incorrect s…

…ubfile Querying CDistributedSuperFile for a subfile that doesn't exist returned a subfile instead of throwing an exception. By not throwing an error, incorrect code that calls querySubFile may be appear to work. This fix modifies querySubFile so that it throws an exception when the subfile number is not valid. Signed-off-by: Shamser Ahmed <[email protected]>
hpcc-systems · Mar 19, 2024 · e3f4a64 · e3f4a64
1 parent 43962f5
commit e3f4a64
Showing 1 changed file with 14 additions and 9 deletions.
diff --git a/dali/base/dadfs.cpp b/dali/base/dadfs.cpp
@@ -6271,22 +6271,27 @@ class CDistributedSuperFile: public CDistributedFileBase<IDistributedSuperFile>
     virtual IDistributedFile &querySubFile(unsigned idx,bool sub) override
     {
         CriticalBlock block (sect);
-        if (sub) {
-            ForEachItemIn(i,subfiles) {
+        if (sub)
+        {
+            unsigned subfilen = idx;
+            ForEachItemIn(i,subfiles)
+            {
                 IDistributedFile &f=subfiles.item(i);
                 IDistributedSuperFile *super = f.querySuperFile();
-                if (super) {
+                if (super)
+                {
                     unsigned ns = super->numSubFiles(true);
-                    if (ns>idx)
-                        return super->querySubFile(idx,true);
-                    idx -= ns;
+                    if (ns>subfilen)
+                        return super->querySubFile(subfilen,true);
+                    subfilen -= ns;
                 }
-                else if (idx--==0)
+                else if (subfilen--==0)
                     return f;
             }
-            // fall through to error
+            throw makeStringExceptionV(-1,"CDistributedSuperFile::querySubFile(%u) for superfile %s - subfile doesn't exist ", idx, logicalName.get());
         }
-        return subfiles.item(idx);
+        else
+            return subfiles.item(idx);
     }
 
     virtual IDistributedFile *querySubFileNamed(const char *name, bool sub) override