X-Git-Url: https://diplodocus.org/git/nmh/blobdiff_plain/a7ec5d546fe5dbf8bc375bdb8d69f5f84789fc7e..553f2f2c99c5d46754cbc7c1628181e7fbc9525a:/uip/mhparse.c?ds=sidebyside

diff --git a/uip/mhparse.c b/uip/mhparse.c
index a3a80f9a..f021b07f 100644
--- a/uip/mhparse.c
+++ b/uip/mhparse.c
@@ -43,6 +43,12 @@ int bogus_mp_content;
 int suppress_extraneous_trailing_semicolon_warning;
 int extraneous_trailing_semicolon;
 
+/* list of preferred type/subtype pairs, for -prefer */
+char *preferred_types[NPREFS],
+     *preferred_subtypes[NPREFS];
+int npreferred;
+
+
 /*
  * Structures for TEXT messages
  */
@@ -104,7 +110,7 @@ static struct k2v EncodingType[] = {
 int find_cache (CT, int, int *, char *, char *, int);
 
 /* mhmisc.c */
-int part_ok (CT, int);
+int part_ok (CT);
 int type_ok (CT, int);
 void content_error (char *, CT, char *, ...);
 
@@ -121,6 +127,7 @@ static int InitGeneric (CT);
 static int InitText (CT);
 static int InitMultiPart (CT);
 static void reverse_parts (CT);
+static void prefer_parts(CT ct);
 static int InitMessage (CT);
 static int InitApplication (CT);
 static int init_encoding (CT, OpenCEFunc);
@@ -1223,8 +1230,10 @@ end_part:
 
 last_part:
     /* reverse the order of the parts for multipart/alternative */
-    if (ct->c_subtype == MULTI_ALTERNATE)
+    if (ct->c_subtype == MULTI_ALTERNATE) {
 	reverse_parts (ct);
+	prefer_parts (ct);
+    }
 
     /*
      * label all subparts with part number, and
@@ -1270,9 +1279,15 @@ last_part:
 
 
 /*
- * reverse the order of the parts of a multipart/alternative
+ * reverse the order of the parts of a multipart/alternative,
+ * presumably to put the "most favored" alternative first, for
+ * ease of choosing/displaying it later on.  from a mail message on
+ * nmh-workers, from kenh:
+ *  "Stock" MH 6.8.5 did not have a reverse_parts() function, but I
+ *  see code in mhn that did the same thing...  Acccording to the RCS
+ *  logs, that code was around from the initial checkin of mhn.c by
+ *  John Romine in 1992, which is as far back as we have."
  */
-
 static void
 reverse_parts (CT ct)
 {
@@ -1289,6 +1304,60 @@ reverse_parts (CT ct)
     }
 }
 
+static void
+move_preferred_part (CT ct, char *type, char *subtype)
+{
+    struct multipart *m = (struct multipart *) ct->c_ctparams;
+    struct part *part, *prev, *head, *nhead, *ntail;
+    struct part h, n;
+    CI ci;
+
+    /* move the matching part(s) to the head of the list:  walk the
+     * list of parts, move matching parts to a new list (maintaining
+     * their order), and finally, concatenate the old list onto the
+     * new.
+     */
+
+    head = &h;
+    nhead = &n;
+
+    head->mp_next = m->mp_parts;
+    nhead->mp_next = NULL;
+    ntail = nhead;
+
+    prev = head;
+    part = head->mp_next;
+    while (part != NULL) {
+	ci = &part->mp_part->c_ctinfo;
+	if (!strcasecmp(ci->ci_type, type) &&
+		(!subtype || !strcasecmp(ci->ci_subtype, subtype))) {
+	    prev->mp_next = part->mp_next;
+	    part->mp_next = NULL;
+	    ntail->mp_next = part;
+	    ntail = part;
+	    part = prev->mp_next;
+	} else {
+	    prev = part;
+	    part = prev->mp_next;
+	}
+    }
+    ntail->mp_next = head->mp_next;
+    m->mp_parts = nhead->mp_next;
+
+}
+
+/*
+ * move parts that match the user's preferences (-prefer) to the head
+ * of the line.  process preferences in reverse so first one given
+ * ends up first in line
+ */
+static void
+prefer_parts(CT ct)
+{
+    int i;
+    for (i = npreferred-1; i >= 0; i--)
+	move_preferred_part(ct, preferred_types[i], preferred_subtypes[i]);
+}