From 57f8977d5cc4d63494061f2ec2e1ab225ab46519 Mon Sep 17 00:00:00 2001
From: Jay Belanger <jay.p.belanger@gmail.com>
Date: Wed, 12 Dec 2007 04:55:20 +0000
Subject: [PATCH] (math-restore-underscores, math-string-restore-underscores):
 New functions. (math-read-factor): Properly check variable names with
 underscores for entries in `math-expr-variable-mapping'.

---
 lisp/ChangeLog         |  5 +++++
 lisp/calc/calc-aent.el | 18 +++++++++++++++++-
 2 files changed, 22 insertions(+), 1 deletion(-)

diff --git a/lisp/ChangeLog b/lisp/ChangeLog
index 12cbb15eac..59b0854751 100644
--- a/lisp/ChangeLog
+++ b/lisp/ChangeLog
@@ -4,6 +4,11 @@
 
 2007-12-11  Jay Belanger  <jay.p.belanger@gmail.com>
 
+	* calc/calc-aent.el (math-restore-underscores)
+	(math-string-restore-underscores): New functions.
+	(math-read-factor): Properly check variable names with underscores
+	for entries in `math-expr-variable-mapping'.
+
 	* calc/calc-lang.el (math-lang-name): New property name.
 
 	* calc/calc.el (calc-set-mode-line): Use `math-lang-name'
diff --git a/lisp/calc/calc-aent.el b/lisp/calc/calc-aent.el
index 697d510ac0..ee9c6e61e4 100644
--- a/lisp/calc/calc-aent.el
+++ b/lisp/calc/calc-aent.el
@@ -1015,6 +1015,19 @@ in Calc algebraic input.")
        (concat (math-match-substring x 1) "-" (math-match-substring x 2)))
     x))
 
+(defun math-restore-underscores (x)
+  "Replace pound signs by underscores in the symbol x.
+If the current Calc language does not allow underscores, return nil."
+  (if (memq calc-language calc-lang-allow-underscores)
+      (intern-soft (math-string-restore-underscores (symbol-name x)))))
+
+(defun math-string-restore-underscores (x)
+  "Replace pound signs by underscores in the string x."
+  (if (string-match "\\`\\(.*\\)#\\(.*\\)\\'" x)
+      (math-string-restore-underscores
+       (concat (math-match-substring x 1) "_" (math-match-substring x 2)))
+    x))
+
 (defun math-read-if (cond op)
   (let ((then (math-read-expr-level 0)))
     (or (equal math-expr-data ":")
@@ -1116,7 +1129,10 @@ in Calc algebraic input.")
 				      sym
 				    (intern (concat "var-"
 						    (symbol-name sym)))))))
-		   (let ((v (assq (nth 1 val) math-expr-variable-mapping)))
+		   (let ((v (or
+                             (assq (nth 1 val) math-expr-variable-mapping)
+                             (assq (math-restore-underscores (nth 1 val))
+                                   math-expr-variable-mapping))))
 		     (and v (setq val (if (consp (cdr v))
 					  (funcall (car (cdr v)) v val)
 					(list 'var
-- 
2.20.1