[elpa] externals/xr 33c5400 5/6: Suppress false positive in repetition of empty string

[Mattias Engdegård]

branch: externals/xr
commit 33c540033e2723668330f474c28a9b2b2e6646fd
Author: Mattias Engdegård <address@hidden>
Commit: Mattias Engdegård <address@hidden>

    Suppress false positive in repetition of empty string
    
    Don't complain about repetition of the empty string, \(?:\)REPOP,
    since that is more likely to be a false positive (from partial parsing
    in relint) than an actual error.
    Dealing with it here rather than in relint is a clear layer violation
    but I don't see a better way.
---
 xr-test.el |  2 +-
 xr.el      | 10 ++++++++--
 2 files changed, 9 insertions(+), 3 deletions(-)

diff --git a/xr-test.el b/xr-test.el
index 82585a0..99c85fa 100644
--- a/xr-test.el
+++ b/xr-test.el
@@ -371,7 +371,7 @@
            (xr-lint "[-A-Z][A-Z-][A-Z-a][^-A-Z][]-a][A-Z---.]")
            '((16 . "Literal `-' not first or last in character alternative"))))
   (should (equal
-           (xr-lint "\\(?:a*b?\\)*\\(c\\|d\\|\\)+\\(^\\|e\\)*")
+           (xr-lint "\\(?:a*b?\\)*\\(c\\|d\\|\\)+\\(^\\|e\\)*\\(?:\\)*")
            '((10 . "Repetition of expression matching an empty string")
              (21 . "Repetition of expression matching an empty string"))))
   (should (equal (xr-lint "\\'*\\<?\\(?:$\\)+")
diff --git a/xr.el b/xr.el
index d97f147..0438257 100644
--- a/xr.el
+++ b/xr.el
@@ -491,7 +491,10 @@ UPPER may be nil, meaning infinity."
                  ((memq (car sequence) xr--zero-width-assertions)
                   (xr--report warnings (match-beginning 0)
                               "Repetition of zero-width assertion"))
-                 ((xr--matches-empty-p (car sequence))
+                 ((and (xr--matches-empty-p (car sequence))
+                       ;; Rejecting repetition of the empty string
+                       ;; suppresses some false positives.
+                       (not (equal (car sequence) "")))
                   (xr--report
                    warnings (match-beginning 0)
                    "Repetition of expression matching an empty string"))))
@@ -519,7 +522,10 @@ UPPER may be nil, meaning infinity."
            ((memq (car sequence) xr--zero-width-assertions)
             (xr--report warnings (match-beginning 0)
                         "Repetition of zero-width assertion"))
-           ((xr--matches-empty-p (car sequence))
+           ((and (xr--matches-empty-p (car sequence))
+                 ;; Rejecting repetition of the empty string
+                 ;; suppresses some false positives.
+                 (not (equal (car sequence) "")))
             (xr--report warnings (match-beginning 0)
                         "Repetition of expression matching an empty string"))))
         (if (looking-at (rx (opt (group (one-or-more digit)))