magit-blame: fix calls from indirect buffers

Make sure that default-directory stays set at the top-level directory.
When magit-blame is called from an indirect buffer, the find-file call
sets default-directory to the file's directory, so the downstream git
call (now from the file's directory) fails when given a path relative to
the top-level directory.

This isn't an issue when magit-blame is called from a buffer visiting a
file.  The call to find-file does not override the default-directory
let-bound by magit-with-toplevel because the file is already being
visited by the current buffer.

Fix this by let-binding the find-file call separately.

While this makes it possible call magit-blame from an indirect buffer,
point is not placed appropriately in the base buffer.  This probably
isn't worth taking the time to fix given that calling magit-blame from
indirect buffer isn't very common (since the above error has yet to be
reported).

1 files changed, 43 insertions, 40 deletions

diff --git a/lisp/magit-blame.el b/lisp/magit-blame.el
index c188aaf..b1c6439 100644
--- a/lisp/magit-blame.el
+++ b/lisp/magit-blame.el
@@ -219,49 +219,52 @@ only arguments available from `magit-blame-popup' should be used.
          (if buffer-file-name
              (user-error "Buffer isn't visiting a tracked file")
            (user-error "Buffer isn't visiting a file"))))))
-  (magit-with-toplevel
+  (let ((toplevel (or (magit-toplevel)
+                      (user-error "Not in git repository"))))
     (if revision
         (magit-find-file revision file)
-      (find-file (expand-file-name file)))
+      (let ((default-directory toplevel))
+        (find-file file)))
     (widen)
-    (when line
-      (setq magit-blame-recursive-p t)
-      (goto-char (point-min))
-      (forward-line (1- line)))
-    (unless magit-blame-mode
-      (setq magit-blame-cache (make-hash-table :test 'equal))
-      (let ((show-headings magit-blame-show-headings))
-        (magit-blame-mode 1)
-        (setq-local magit-blame-show-headings show-headings))
-      (message "Blaming...")
-      (let ((magit-process-popup-time -1)
-            (inhibit-magit-refresh t))
-        (magit-run-git-async
-         "blame" "--incremental" args
-         "-L" (format "%s,%s"
-                      (line-number-at-pos (window-start))
-                      (line-number-at-pos (1- (window-end))))
-         revision "--" file))
-      (setq magit-blame-process magit-this-process)
-      (set-process-filter magit-this-process 'magit-blame-process-filter)
-      (set-process-sentinel
-       magit-this-process
-       `(lambda (process event)
-          (when (memq (process-status process) '(exit signal))
-            (magit-process-sentinel process event)
-            (magit-blame-assert-buffer process)
-            (with-current-buffer (process-get process 'command-buf)
-              (when magit-blame-mode
-                (let ((magit-process-popup-time -1)
-                      (inhibit-magit-refresh t)
-                      (default-directory ,default-directory))
-                  (magit-run-git-async "blame" "--incremental" ,@args
-                                       ,revision "--" ,file))
-                (setq magit-blame-process magit-this-process)
-                (set-process-filter
-                 magit-this-process 'magit-blame-process-filter)
-                (set-process-sentinel
-                 magit-this-process 'magit-blame-process-sentinel)))))))))
+    (let ((default-directory toplevel))
+      (when line
+        (setq magit-blame-recursive-p t)
+        (goto-char (point-min))
+        (forward-line (1- line)))
+      (unless magit-blame-mode
+        (setq magit-blame-cache (make-hash-table :test 'equal))
+        (let ((show-headings magit-blame-show-headings))
+          (magit-blame-mode 1)
+          (setq-local magit-blame-show-headings show-headings))
+        (message "Blaming...")
+        (let ((magit-process-popup-time -1)
+              (inhibit-magit-refresh t))
+          (magit-run-git-async
+           "blame" "--incremental" args
+           "-L" (format "%s,%s"
+                        (line-number-at-pos (window-start))
+                        (line-number-at-pos (1- (window-end))))
+           revision "--" file))
+        (setq magit-blame-process magit-this-process)
+        (set-process-filter magit-this-process 'magit-blame-process-filter)
+        (set-process-sentinel
+         magit-this-process
+         `(lambda (process event)
+            (when (memq (process-status process) '(exit signal))
+              (magit-process-sentinel process event)
+              (magit-blame-assert-buffer process)
+              (with-current-buffer (process-get process 'command-buf)
+                (when magit-blame-mode
+                  (let ((magit-process-popup-time -1)
+                        (inhibit-magit-refresh t)
+                        (default-directory ,default-directory))
+                    (magit-run-git-async "blame" "--incremental" ,@args
+                                         ,revision "--" ,file))
+                  (setq magit-blame-process magit-this-process)
+                  (set-process-filter
+                   magit-this-process 'magit-blame-process-filter)
+                  (set-process-sentinel
+                   magit-this-process 'magit-blame-process-sentinel))))))))))
 
 (defun magit-blame-process-sentinel (process event)
   (let ((status (process-status process)))