fix: nicer structure and warning is only emitted when necessary

Author: kandolfp

src/core/jupyter/jupyter.ts

@@ -1555,20 +1555,22 @@ async function mdFromCodeCell(
 
     for (const { index, output } of sortedOutputs) {
       // compute output label
-      const outputLabel = label &&
+      let outputLabel_tmp = label;
+      if (label &&
         (
           labelCellContainer ||
           (Array.isArray(sortedOutputs) && (sortedOutputs.length > 1))
         ) &&
-        isDisplayData(output)
-        ? (label + "-" + nextOutputSuffix++)
-        : label;
-      // If the user specifies a top-level array for images but also labels give a warning.
-      if (labelCellContainer === false &&
-        (Array.isArray(sortedOutputs) == true && (sortedOutputs.length > 1))
-      ) {
-        warning("Warning: using multiple top-level figures with labels might result in unwanted behaviour.")
+        isDisplayData(output)) {
+        outputLabel_tmp = label + "-" + nextOutputSuffix++;
+        // If the user specifies a top-level array for images but also labels give a warning.
+        if (labelCellContainer === false &&
+          (Array.isArray(sortedOutputs) == true && (sortedOutputs.length > 1))
+        ) {
+          warning("Warning: using multiple top-level figures with labels might result in unwanted behaviour: " + label)
+        }
       }
+      const outputLabel = outputLabel_tmp
       // If this output has been marked to not be displayed
       // just continue
       if (output.metadata?.[kQuartoOutputDisplay] === false) {