org-src.el: Fix special editing of LaTeX fragments

* lisp/org-macs.el (org-do-remove-indentation): Add optional argument
to skip the first line.
* lisp/org-src.el (org-src--coordinates): Fix coordinates for inline
LaTeX fragments.
(org-src--contents-for-write-back): Do not indent first line for LaTeX
fragments.
(org-src--edit-element): Compute block-indentation according to parent
for LaTeX fragments.  Skip first line when removing common indentation
for LaTeX fragments.

lisp/org-macs.el

@@ -326,17 +326,19 @@ it for output."
 
 ;;; Indentation
 
-(defun org-do-remove-indentation (&optional n)
+(defun org-do-remove-indentation (&optional n skip-fl)
   "Remove the maximum common indentation from the buffer.
 When optional argument N is a positive integer, remove exactly
-that much characters from indentation, if possible.  Return nil
-if it fails."
+that much characters from indentation, if possible.  When
+optional argument SKIP-FL is non-nil, skip the first
+line.  Return nil if it fails."
   (catch :exit
     (goto-char (point-min))
     ;; Find maximum common indentation, if not specified.
     (let ((n (or n
 		 (let ((min-ind (point-max)))
 		   (save-excursion
+                     (when skip-fl (forward-line))
 		     (while (re-search-forward "^[ \t]*\\S-" nil t)
 		       (let ((ind (current-indentation)))
 			 (if (zerop ind) (throw :exit nil)
@@ -344,6 +346,7 @@ if it fails."
 		   min-ind))))
       (if (zerop n) (throw :exit nil)
 	;; Remove exactly N indentation, but give up if not possible.
+        (when skip-fl (forward-line))
 	(while (not (eobp))
 	  (let ((ind (progn (skip-chars-forward " \t") (current-column))))
 	    (cond ((eolp) (delete-region (line-beginning-position) (point)))

lisp/org-src.el

@@ -327,7 +327,8 @@ a cons cell (LINE . COLUMN) or symbol `end'.  See also
   (if (>= pos end) 'end
     (org-with-wide-buffer
      (goto-char (max beg pos))
-     (cons (count-lines beg (line-beginning-position))
+     (cons (count-lines (save-excursion (goto-char beg) (line-beginning-position))
+                        (line-beginning-position))
 	   ;; Column is relative to the end of line to avoid problems of
 	   ;; comma escaping or colons appended in front of the line.
 	   (- (point) (min end (line-end-position)))))))
@@ -445,6 +446,7 @@ Assume point is in the corresponding edit buffer."
 		  org-src--content-indentation
 		0))))
 	(use-tabs? (and (> org-src--tab-width 0) t))
+        (preserve-fl (eq org-src--source-type 'latex-fragment))
 	(source-tab-width org-src--tab-width)
 	(contents (org-with-wide-buffer
                    (let ((eol (line-end-position)))
@@ -466,7 +468,8 @@ Assume point is in the corresponding edit buffer."
       ;; Add INDENTATION-OFFSET to every line in buffer,
       ;; unless indentation is meant to be preserved.
       (when (> indentation-offset 0)
-	(while (not (eobp))
+	(when preserve-fl (forward-line))
+        (while (not (eobp))
 	  (skip-chars-forward " \t")
           (when (or (not (eolp))                               ; not a blank line
                     (and (eq (point) (marker-position marker)) ; current line
@@ -518,7 +521,13 @@ Leave point in edit buffer."
 	     (source-tab-width (if indent-tabs-mode tab-width 0))
 	     (type (org-element-type datum))
 	     (block-ind (org-with-point-at (org-element-property :begin datum)
-			  (current-indentation)))
+                          (cond
+                           ((save-excursion (skip-chars-backward " \t") (bolp))
+			    (current-indentation))
+                           ((org-element-property :parent datum)
+                            (org--get-expected-indentation
+                             (org-element-property :parent datum) nil))
+                           (t (current-indentation)))))
 	     (content-ind org-edit-src-content-indentation)
              (blank-line (save-excursion (beginning-of-line)
                                          (looking-at-p "^[[:space:]]*$")))
@@ -548,7 +557,8 @@ Leave point in edit buffer."
 	(insert contents)
 	(remove-text-properties (point-min) (point-max)
 				'(display nil invisible nil intangible nil))
-	(unless preserve-ind (org-do-remove-indentation))
+	(let ((lf (eq type 'latex-fragment)))
+          (unless preserve-ind (org-do-remove-indentation (and lf block-ind) lf)))
 	(set-buffer-modified-p nil)
 	(setq buffer-file-name nil)
 	;; Initialize buffer.