Add proper error checking in asciihex2int functions

src/cli/scanner.l

@@ -17,9 +17,26 @@ hextail		({digit}|{alpha}){1,8}
 hex1		0[xX]{hextail}
 hex2		${hextail}
 
+
 %%
-{hex1}      { yylval.number = asciihex2int(yytext); return NUMBER; }
-{hex2}      { yylval.number = asciihex2int(&yytext[1]); return NUMBER; }
+{hex1}      {
+                /*
+                 * No need to check return value of asciihex2int, because lex
+                 * always passes a valid ASCII hex string.
+                 */
+                yylval.number = asciihex2int(&yytext[2]); /* Skip "0x" prefix */
+                return NUMBER;
+            }
+{hex2}      {
+                /*
+                 * No need to check return value of asciihex2int, because lex
+                 * always passes a valid ASCII hex string.
+                 */
+                yylval.number = asciihex2int(&yytext[1]); /* Skip "$" prefix */
+                return NUMBER;
+            }
+
+
 [0-9]+      { yylval.number = atoi(yytext); return NUMBER; }
 [h?]        return TOK_HELP;
 sb          return TOK_SB;

src/common/hexfile.c

@@ -29,6 +29,12 @@
 
 static int asciihex2int_error;
 
+int
+asciihex2int_get_error(void)
+{
+	return asciihex2int_error;
+}
+
 /* Convert integer to ASCII hex string. */
 void
 int2asciihex(int val, char *str, int width)
@@ -43,35 +49,24 @@ int2asciihex(int val, char *str, int width)
 		sprintf(str , "Err");
 }
 
-/* Convert ASCII hex string to integer. */
-int
-asciihex2int(char *str)
-{
-	int val;
-	int rc;
-
-	rc = sscanf(str, "%X", &val);
-
-	if (rc == 0) {
-		log_err("ASCII to hex conversion failure");
-		asciihex2int_error = true;
-	}
-
-	return val;
-}
-
-/* Convert an ascii string to an hexadecimal number. */
+/*
+ * Convert ASCII string in hexadecimal notation to integer, up to length
+ * characters.
+ * The string contains only [0-9] and [a-f] characters (no "0x" prefix).
+ */
 static unsigned int
-asciihex2int_len(char *istring, int length)
+asciihex2int_len(char *str, int length)
 {
 	unsigned int result = 0;
 	int i, ascii_code;
 
-	if (!length || (length > (int) strlen(istring)))
-		length = strlen(istring);
+	asciihex2int_error = false;
+
+	if (!length || (length > (int) strlen(str)))
+		length = strlen(str);
 
 	for (i = 0; i < length; i++) {
-		ascii_code = istring[i];
+		ascii_code = str[i];
 		if (ascii_code > 0x39)
 			ascii_code &= 0xDF;
 
@@ -86,11 +81,23 @@ asciihex2int_len(char *istring, int length)
 		} else {
 			log_err("ASCII to hex conversion failure");
 			asciihex2int_error = true;
+			return 0;
 		}
 	}
 	return result;
 }
 
+/*
+ * Convert ASCII string in hexadecimal notation to integer, up to \0 end character.
+ * The string must not contain prefix "0x", only [0-9] and [a-f] characters.
+ */
+unsigned int
+asciihex2int(char *str)
+{
+	/* Set length to zero to use full length of string. */
+	return asciihex2int_len(str, 0);
+}
+
 /*
  * Return value:
  *   true:  success

src/common/hexfile.h

@@ -10,10 +10,13 @@
 #ifndef HEXFILE_H
 #define HEXFILE_H 1
 
+int
+asciihex2int_get_error(void);
+
 void
 int2asciihex(int val, char *str, int width);
 
-int
+unsigned int
 asciihex2int(char *str);
 
 int

src/gtk/memwin.c

@@ -104,6 +104,8 @@ memwin_cell_edited(GtkCellRendererText *cell, gchar *path_string,
 
 	/* Get base address. */
 	gtk_tree_model_get(model, &iter, COL_ADDRESS, &str, -1);
+
+	/* No need to check error, has already been validated. */
 	address = asciihex2int(str);
 
 	/* Convert column number (1, 2, 3...) to index (0, 1, 2...) */
@@ -115,9 +117,12 @@ memwin_cell_edited(GtkCellRendererText *cell, gchar *path_string,
 
 	/* Convert new value (asciihex) to integer. */
 	new = asciihex2int(new_str);
-	if ((new < 0) || (new > 255)) {
-		log_info("  new value: out of range");
-		new = old; /* Put back old value... */
+	if (asciihex2int_get_error()) {
+		log_warn("  new value: invalid");
+		return;
+	} else if ((new < 0) || (new > 255)) {
+		log_warn("  new value: out of range");
+		return;
 	} else {
 		log_info("  new value: $%02X", new);
 	}

src/gtk/pgmwin.c

@@ -134,6 +134,7 @@ pgmwin_sel_changed_event(GtkWidget *widget, GdkEvent *event, gpointer data)
 		gtk_tree_model_get(model, &iter, COL_ADDR, &str_addr, -1);
 
 		/* Convert hex address in ASCII to integer. */
+		/* No need to check error, has already been validated. */
 		val = asciihex2int(str_addr);
 
 		log_debug("  row address is: $%04X", val);

src/gtk/pswwin.c

@@ -110,9 +110,12 @@ pswwin_cell_edited(GtkCellRendererText *cell, gchar *path_string,
 	/* Convert new value (asciihex) to integer. */
 	new = asciihex2int(new_str);
 
-	if ((new != 0) && (new != 1)) {
-		log_info("  new value: out of range");
-		new = old; /* Put back old value... */
+	if (asciihex2int_get_error()) {
+		log_warn("  new value: invalid");
+		return;
+	} else if ((new != 0) && (new != 1)) {
+		log_warn("  new value: out of range");
+		return;
 	} else {
 		log_info("  new value: %d", new);
 	}

src/gtk/regwin.c

@@ -88,10 +88,16 @@ regwin_cell_edited(GtkCellRendererText *cell, gchar *path_string,
 	/* Read current (old) value. */
 	gtk_tree_model_get(model, &iter, COL_VAL, &str, -1);
 
+	/* No need to check error, has already been validated. */
 	old = asciihex2int(str);
 	log_info("  old value: $%04X", old);
 
 	new = asciihex2int(new_str);
+	if (asciihex2int_get_error()) {
+		log_warn("  new value: invalid");
+		return;
+	}
+
 	log_info("  new value: $%04X", new);
 
 	/* Store new value in emulator register (if in range). */