Merge branch 'master' of orgmode.org:org-mode

lisp/ob-sql.el

@@ -123,7 +123,8 @@ This function is called by `org-babel-execute-src-block'."
 				    (org-babel-process-file-name in-file)
 				    (org-babel-process-file-name out-file)))
 		    ('postgresql (format
-				  "psql --set=\"ON_ERROR_STOP=1\" -A -P footer=off -F \"\t\"  -f %s -o %s %s"
+				  "psql --set=\"ON_ERROR_STOP=1\" %s -A -P footer=off -F \"\t\"  -f %s -o %s %s"
+				  (if colnames-p "" "-t")
 				  (org-babel-process-file-name in-file)
 				  (org-babel-process-file-name out-file)
 				  (or cmdline "")))

lisp/ox-md.el

@@ -255,7 +255,8 @@ a communication channel."
 	      (off "[ ] "))
 	    (let ((tag (org-element-property :tag item)))
 	      (and tag (format "**%s:** "(org-export-data tag info))))
-	    (org-trim (replace-regexp-in-string "^" "    " contents)))))
+	    (and contents
+		 (org-trim (replace-regexp-in-string "^" "    " contents))))))