[RF] Fix RooAbsCollection::contentsString() for empty collections

TomasDado · guitargeek · commit 029451f78a70 · 2025-10-25T12:13:48.000+02:00
Closes #20189.
diff --git a/roofit/roofitcore/src/RooAbsCollection.cxx b/roofit/roofitcore/src/RooAbsCollection.cxx
@@ -1154,7 +1154,9 @@ std::string RooAbsCollection::contentsString() const
     retVal += ",";
   }
 
-  retVal.erase(retVal.end()-1);
+  if (!retVal.empty()) {
+    retVal.erase(retVal.end()-1);
+  }
 
   return retVal;
 }

Original file line number	Diff line number	Diff line change
`@@ -1154,7 +1154,9 @@ std::string RooAbsCollection::contentsString() const`
`1154`	`1154`	`retVal += ",";`
`1155`	`1155`	`}`
`1156`	`1156`
`1157`		`- retVal.erase(retVal.end()-1);`
	`1157`	`+ if (!retVal.empty()) {`
	`1158`	`+ retVal.erase(retVal.end()-1);`
	`1159`	`+ }`
`1158`	`1160`
`1159`	`1161`	`return retVal;`
`1160`	`1162`	`}`