Ignoring Content-Transfer-Encoding headers with missing values.

A Content-Transfer-Encoding header with a missing value
would be handled the same as an unknown encoding value:
a message would be included in the body of the converted message
stating the encoding was unknown as well as the unknown encoding
value. However, if the value was missing, hypermail would use
the value of an unitialized variable.

Author: jkbzh

Changelog

@@ -4,6 +4,12 @@ Version Changes for Hypermail
 HYPERMAIL VERSION 2.4.0:
 ============================
 
+2019-12-19 Jose Kahan
+	* src/parse.c
+	parsemail(): a Content-Transfer-Encoding header with a missing value
+	would output a random string when generating unsupported encoding
+	body message.
+
 2019-11-22 Jose Kahan
 	* src/print.c
 	printsubject() / printdates(): the "by suject" and "by dates" views

src/parse.c

@@ -2466,7 +2466,13 @@ int parsemail(char *mbox,	/* file name */
 			    /* Unknown format, we use default decoding */
 			    char code[64];
 
-			    sscanf(ptr, "%63s", code);
+			    /* is there any value for content-encoding or is it missing? */
+			    if (*ptr) {
+			      sscanf(ptr, "%63s", code);
+			    } else {
+			      code[0] = '\0';
+			    }
+			    
                             snprintf(line, sizeof(line_buf) - set_ietf_mbox,
 				     " ('%s' %s)\n", code, 
                                      lang[MSG_ENCODING_IS_NOT_SUPPORTED]);