From d32d0b01b8b8ee00fbbca02115a6e103d4542556 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Alex=20Benn=C3=A9e?= <alex@bennee.com>
Date: Mon, 4 Nov 2013 14:50:07 +0000
Subject: [PATCH] eproject.el: don't barf on non file backed buffers

While eproject-maybe-turn-on is only called on various mode hooks it
breaks on temporary buffers if they use a programming mode. One such
example is when exporting an org-mode document with embedded source
code.

This stops it throwing an error by skipping the attempt if there is no
associated (buffer-file-name) for the buffer.
---
 eproject.el | 25 +++++++++++++------------
 1 file changed, 13 insertions(+), 12 deletions(-)

diff --git a/eproject.el b/eproject.el
index f34b921..6edc709 100644
--- a/eproject.el
+++ b/eproject.el
@@ -549,15 +549,16 @@ else through unchanged."
   "Turn on eproject for the current buffer, if it is in a project."
   (interactive)
   (let (bestroot besttype (set-before (mapcar #'car eproject-attributes-alist)))
-    (loop for type in (eproject--all-types)
-          do (let ((root (eproject--run-project-selector type)))
-               (when (and root
-                          (or (not bestroot)
-                              ;; longest filename == best match (XXX:
-                              ;; need to canonicalize?)
-                              (> (length root) (length bestroot))))
-                 (setq bestroot root)
-                 (setq besttype type))))
+    (when (buffer-file-name (current-buffer))
+      (loop for type in (eproject--all-types)
+            do (let ((root (eproject--run-project-selector type)))
+                 (when (and root
+                            (or (not bestroot)
+                                ;; longest filename == best match (XXX:
+                                ;; need to canonicalize?)
+                                (> (length root) (length bestroot))))
+                   (setq bestroot root)
+                   (setq besttype type)))))
     (when bestroot
       (setq eproject-root (file-name-as-directory bestroot))
 
@@ -566,7 +567,7 @@ else through unchanged."
       (condition-case e
           (eproject--init-attributes eproject-root besttype)
         (error (display-warning 'warning
-            (format "There was a problem setting up the eproject attributes for this project: %s" e))))
+                                (format "There was a problem setting up the eproject attributes for this project: %s" e))))
 
       ;; with :name and :type set, it's now safe to turn on eproject
       (eproject-mode 1)
@@ -577,8 +578,8 @@ else through unchanged."
       (condition-case e
           (eproject--setup-local-variables)
         (error (display-warning 'warning
-          (format "Problem initializing project-specific local-variables in %s: %s"
-                  (eproject--buffer-file-name) e))))
+                                (format "Problem initializing project-specific local-variables in %s: %s"
+                                        (eproject--buffer-file-name) e))))
 
       ;; run the first-buffer hooks if this is the first time we've
       ;; seen this particular project root.