Reduce size of lint message

Author: PrestonFrom

clippy_lints/src/matches/significant_drop_in_scrutinee.rs

@@ -8,7 +8,7 @@ use rustc_hir::{Expr, ExprKind, MatchSource};
 use rustc_lint::{LateContext, LintContext};
 use rustc_middle::ty::subst::GenericArgKind;
 use rustc_middle::ty::{Ty, TypeAndMut};
-use rustc_span::Span;
+use rustc_span::{Span};
 
 use super::SIGNIFICANT_DROP_IN_SCRUTINEE;
 
@@ -22,13 +22,11 @@ pub(super) fn check<'tcx>(
         for found in suggestions {
             span_lint_and_then(cx, SIGNIFICANT_DROP_IN_SCRUTINEE, found.found_span, message, |diag| {
                 set_diagnostic(diag, cx, expr, found);
+                let s = Span::new(expr.span.hi(), expr.span.hi(), expr.span.ctxt(), None);
                 diag.span_label(
-                    expr.span,
-                    "temporaries in a match scrutinee are not dropped until the end of the \
-                    match, so side effects from dropping such temporaries are delayed. \
-                    Deadlocks can occur if a lock guard is created in the scrutinee and a new \
-                    lock guard for the same mutex is created in a match arm. \
-                    For more information, see https://rust-lang.github.io/rust-clippy/master/index.html#significant_drop_in_scrutinee");
+                    s,
+                    "temporary lives until here. If mutex is locked within block, deadlocks can occur.",
+                );
             });
         }
     }
@@ -87,9 +85,9 @@ fn has_significant_drop_in_scrutinee<'tcx, 'a>(
     let mut helper = SigDropHelper::new(cx);
     helper.find_sig_drop(scrutinee).map(|drops| {
         let message = if source == MatchSource::Normal {
-            "temporary with significant drop in match scrutinee"
+            "temporary with drop impl with side effects in match scrutinee lives to end of block"
         } else {
-            "temporary with significant drop in for loop"
+            "temporary with drop impl with side effects in for loop condition lives to end of block"
         };
         (drops, message)
     })