From b5d4a7dd355b8fdc76756e6ec3cb55b165da59b3 Mon Sep 17 00:00:00 2001
From: Josh Davies <jodavies@users.noreply.github.com>
Date: Tue, 31 Mar 2026 11:53:41 +0100
Subject: [PATCH] fix: forbid non-dollar names starting with $

---
 check/fixes.frm   | 15 +++++++++++++++
 sources/comexpr.c |  7 +++----
 sources/names.c   |  1 +
 3 files changed, 19 insertions(+), 4 deletions(-)

diff --git a/check/fixes.frm b/check/fixes.frm
index f2793f7c..801d09e3 100644
--- a/check/fixes.frm
+++ b/check/fixes.frm
@@ -4490,6 +4490,21 @@ assert warning?("Excess information in symmetric properties")
 assert warning?("Illegal information in number of arguments properties")
 assert warning?("Undefined $-variable")
 *--#] Issue766 : 
+*--#[ Issue782 : 
+S $s;
+V $v;
+I $i;
+F $f;
+Set $ss;
+Local $test = 1;
+.end
+assert compile_error?("Illegally formed name in symbol statement")
+assert compile_error?("Illegally formed name in vector statement")
+assert compile_error?("Illegally formed name in index statement")
+assert compile_error?("Illegally formed function/tensor name")
+assert compile_error?("Illegal name for set")
+assert compile_error?("Illegal name for expression")
+*--#] Issue782 : 
 *--#[ Issue796 : 
 * Regression: the fix for 796 deadlocks here:
 Symbol x;
diff --git a/sources/comexpr.c b/sources/comexpr.c
index f352b447..2d608f8b 100644
--- a/sources/comexpr.c
+++ b/sources/comexpr.c
@@ -112,12 +112,11 @@ int DoExpr(UBYTE *inp, int type, int par)
 		else p++;
 	}
 	if ( *p ) {		/* Variety with the = sign */
-		if ( ( q = SkipAName(inp) ) == 0 || q[-1] == '_' ) {
+		q = SkipAName(inp);
+		if ( *inp == '$' || q == 0 || q[-1] == '_' ) {
 			MesPrint("&Illegal name for expression");
 			error = 1;
-			if ( q[-1] == '_' ) {
-				while ( FG.cTable[*q] < 2 || *q == '_' ) q++;
-			}
+			return(error);
 		}
 		else {
 			c = *q; *q = 0;
diff --git a/sources/names.c b/sources/names.c
index c2cf3c7b..3d52dbf2 100644
--- a/sources/names.c
+++ b/sources/names.c
@@ -3261,6 +3261,7 @@ int TestName(UBYTE *name)
 	}
 	while ( *name ) {
 		if ( *name == '_' ) return(-1);
+		if ( *name == '$' ) return(-1);
 		name++;
 	}
 	return(0);