Alist key mismatch leads to "No coverage data found" message.

[FinnG]

I installed cov through MELPA today; I have a repository with a structure resembling the following:

<repo>/subdir/source_file.c
<repo>/coverage/source_file.c.gcov

As such, I've set my cov-coverage-file-paths variable to the following:

("../coverage" "coverage")

When I open subdir/source_file.c and enable cov-mode I get an error No coverage data found for <repo>/subdir/source_file.c., despite there being a *.gcov file available. Some cursory inspection with edebug shows that the alist in the relevant cov-data-coverage slot has key source_file.c, but the lookup in cov--get-buffer-coverage is looking for subdir/source_file.c.

This causes the key lookup to fail and cov-set-overlays prints the above error message.

[FinnG]

diff --git a/cov.el b/cov.el
index 38d4aff..2ec6f6c 100644
--- a/cov.el
+++ b/cov.el
@@ -418,9 +418,9 @@ it if necessary, or reloading if the file has changed."

         (add-hook 'kill-buffer-hook 'cov-kill-buffer-hook)
         ;; Find file coverage.
-        (let ((common (f-common-parent (list file (buffer-file-name)))))
-          (cdr (assoc (string-remove-prefix common (buffer-file-name))
-                      (cov-data-coverage stored-data))))))))
+        (cdr (assoc (file-name-nondirectory (buffer-file-name))
+                    (cov-data-coverage stored-data)))))))

 (defun cov--load-coverage (coverage file &rest ignore-current)
   "Load coverage data into COVERAGE from FILE.

This patch appears to fix the issue for me. I ran this through the test suite and it seems there's a failing test that appears to be unrelated to this issue (#24). I'd be happy to submit this as a pull request, but will await advice depending on the outcome of #24!