fix: Typo in transfer validation

plate-tool-lib/src/transfer_region.rs

@@ -131,10 +131,8 @@ impl TransferRegion {
     pub fn calculate_map(&self) -> Box<dyn Fn(Well) -> Option<Vec<Well>> + '_> {
         // By validating first, we have a stronger guarantee that
         // this function will not panic. :)
-        // log::debug!("Validating: {:?}", self.validate());
         if let Err(msg) = self.validate() {
-            eprintln!("{}", msg);
-            eprintln!("This transfer will be empty.");
+            log::error!("{}\nThis transfer will be empty.", msg);
             return Box::new(|_| None);
         }
 
@@ -308,11 +306,15 @@ impl TransferRegion {
                     // log::debug!("s1.1: {}, max.1: {}", s1.1, source_max.1);
                     return Err("Source region is out-of-bounds! (Too wide)");
                 }
+
+                if il_dest == (0,0) {
+                    return Err("Refusing to pool both dimensions in a rectangular transfer!\nPlease select a point in the destination plate.")
+                }
             }
             Region::Custom(_) => return Ok(()),
         }
 
-        if il_source.0 == 0 || il_dest.1 == 0 {
+        if il_source.0 == 0 || il_source.1 == 0 {
             return Err("Source interleave cannot be zero!");
         }