maddr, mhdr: requote display names when needed

maddr.c

@@ -13,6 +13,29 @@ static char defaulthflags[] = "from:sender:reply-to:to:cc:bcc:"
     "resent-from:resent-sender:resent-to:resent-cc:resent-bcc:";
 static char *hflag = defaulthflags;
 
+void
+print_quoted(char *s)
+{
+	char *t;
+
+	for (t = s; *t; t++)
+                if ((unsigned char)*t < 32 || strchr("()<>[]:;@\\,.\"", *t))
+			goto quote;
+	
+	printf("%s", s);
+	return;
+
+quote:
+	putchar('"');
+	for (t = s; *t; t++) {
+		if (*t == '"' || *t == '\\')
+			putchar('\\');
+		putchar(*t);
+	}
+	putchar('"');
+
+}
+
 void
 addr(char *file)
 {
@@ -41,10 +64,12 @@ addr(char *file)
 				if (disp && addr && strcmp(disp, addr) == 0)
 					disp = 0;
 				if (disp && addr) {
-					if (aflag)
+					if (aflag) {
 						printf("%s\n", addr);
-					else
-						printf("%s <%s>\n", disp, addr);
+					} else {
+						print_quoted(disp);
+						printf(" <%s>\n", addr);
+					}
 				} else if (addr) {
 					printf("%s\n", addr);
 				}

mhdr.c

@@ -58,6 +58,29 @@ headerall(struct message *msg)
 	blaze822_free(msg);
 }
 
+void
+print_quoted(char *s)
+{
+	char *t;
+
+	for (t = s; *t; t++)
+                if ((unsigned char)*t < 32 || strchr("()<>[]:;@\\,.\"", *t))
+			goto quote;
+	
+	printf("%s", s);
+	return;
+
+quote:
+	putchar('"');
+	for (t = s; *t; t++) {
+		if (*t == '"' || *t == '\\')
+			putchar('\\');
+		putchar(*t);
+	}
+	putchar('"');
+
+}
+
 void
 print_addresses(char *s)
 {
@@ -74,10 +97,12 @@ print_addresses(char *s)
 		if (Hflag && addr)
 			printf("%s\t", curfile);
 
-		if (disp && addr)
-			printf("%s <%s>\n", disp, addr);
-		else if (addr)
+		if (disp && addr) {
+			print_quoted(disp);
+			printf(" <%s>\n", addr);
+		} else if (addr) {
 			printf("%s\n", addr);
+		}
 	}
 }