Cherrypick of Emacs fix for issue #380 (#386)

* (editorconfig-core-get-properties-hash): Simplify

* editorconfig-core.el (editorconfig-core-get-properties-hash):
Remove code that sets tab_width from indent_size and vice-versa,
since that's better done (and is done) later in `editorconfig.el`.
Also remove autoload cookie since this file is already
`require`d from the caller anyway.
Remove`confversion` arg, not used.
(editorconfig-core-get-properties): Move to `editorconfig-el`.

* bin/editorconfig-el (editorconfig-core-get-properties):
New function taken from `editorconfig-core.el`.

* editorconfig-core-handle.el: Fix silent misparse

Cherrypick of Emacs commit e233513d2821.
See #380

* lisp/editorconfig-core-handle.el (editorconfig-core-handle--parse-file):
Fix regexp to not inadvertently match LF.  Remove an O(N²) complexity.
Use `line-number-at-pos`.

* lisp/editorconfig.el (editorconfig--get-coding-system): Don't let
errors propagate.

---------

Co-authored-by: Hong Xu <hong@topbug.net>

Author: monnier

editorconfig-core-handle.el

@@ -169,10 +169,7 @@ If CONF is not found return nil."
             ;; nil when pattern not appeared yet, "" when pattern is empty ("[]")
             (pattern nil)
             ;; Alist of properties for current PATTERN
-            (props ())
-
-            ;; Current line num
-            (current-line-number 1))
+            (props ()))
         (while (not (eobp))
           (skip-chars-forward " \t\f")
           (cond
@@ -190,7 +187,7 @@ If CONF is not found return nil."
               (setq props nil)
               (setq pattern newpattern)))
 
-           ((looking-at "\\([^=: \t][^=:]*\\)[ \t]*[=:][ \t]*\\(.*?\\)[ \t]*$")
+           ((looking-at "\\([^=: \n\t][^=:\n]*\\)[ \t]*[=:][ \t]*\\(.*?\\)[ \t]*$")
             (let ((key (downcase (string-trim (match-string 1))))
                   (value (match-string 2)))
               (if pattern
@@ -200,12 +197,10 @@ If CONF is not found return nil."
                       top-props))))
 
            (t (error "Error while reading config file: %s:%d:\n    %s\n"
-                     conf current-line-number
+                     conf (line-number-at-pos)
                      (buffer-substring-no-properties (line-beginning-position)
                                                      (line-end-position)))))
-          (setq current-line-number (1+ current-line-number))
-          (goto-char (point-min))
-          (forward-line (1- current-line-number)))
+          (forward-line 1))
         (when pattern
           (push (make-editorconfig-core-handle-section
                  :name pattern

editorconfig.el

@@ -837,17 +837,21 @@ F is that function, and FILENAME and ARGS are arguments passed to F."
 (defun editorconfig--get-coding-system (&optional _size)
   "Return the coding system to use according to EditorConfig.
 Meant to be used on `auto-coding-functions'."
-  (when (and (stringp auto-coding-file-name)
-             (file-name-absolute-p auto-coding-file-name)
-	     ;; Don't recurse infinitely.
-	     (not (member auto-coding-file-name
-	                  editorconfig--getting-coding-system)))
-    (let* ((editorconfig--getting-coding-system
-            (cons auto-coding-file-name editorconfig--getting-coding-system))
-           (props (editorconfig-call-get-properties-function
-                   auto-coding-file-name)))
-      (editorconfig-merge-coding-systems (gethash 'end_of_line props)
-                                         (gethash 'charset props)))))
+  ;; Not only we don't want that an error in the `.editorconfig' file
+  ;; prevents opening a file but we don't want an error to be dropped on
+  ;; the floor by some `ignore-errors' higher up.
+  (with-demoted-errors "EditorConfig: %S"
+    (when (and (stringp auto-coding-file-name)
+               (file-name-absolute-p auto-coding-file-name)
+	       ;; Don't recurse infinitely.
+	       (not (member auto-coding-file-name
+	                    editorconfig--getting-coding-system)))
+      (let* ((editorconfig--getting-coding-system
+              (cons auto-coding-file-name editorconfig--getting-coding-system))
+             (props (editorconfig-call-get-properties-function
+                     auto-coding-file-name)))
+        (editorconfig-merge-coding-systems (gethash 'end_of_line props)
+                                           (gethash 'charset props))))))
 
 ;;;###autoload
 (define-minor-mode editorconfig-mode