Adds capability to edit x-labels inside mutt, and to sort by label.

OPS

@@ -57,6 +57,7 @@ OP_DELETE_THREAD "delete all messages in thread"
 OP_DISPLAY_ADDRESS "display full address of sender"
 OP_DISPLAY_HEADERS "display message and toggle header weeding"
 OP_DISPLAY_MESSAGE "display a message"
+OP_EDIT_LABEL "add, change, or delete a message's label"
 OP_EDIT_MESSAGE "edit the raw message"
 OP_EDITOR_BACKSPACE "delete the char in front of the cursor"
 OP_EDITOR_BACKWARD_CHAR "move the cursor one character to the left"

commands.c

@@ -533,9 +533,9 @@ int mutt_select_sort (int reverse)
   int method = Sort; /* save the current method in case of abort */
 
   switch (mutt_multi_choice (reverse ?
-			     _("Rev-Sort (d)ate/(f)rm/(r)ecv/(s)ubj/t(o)/(t)hread/(u)nsort/si(z)e/s(c)ore/s(p)am?: ") :
-			     _("Sort (d)ate/(f)rm/(r)ecv/(s)ubj/t(o)/(t)hread/(u)nsort/si(z)e/s(c)ore/s(p)am?: "),
-			     _("dfrsotuzcp")))
+			     _("Rev-Sort Date/Frm/Recv/Subj/tO/Thread/Unsort/siZe/sCore/sPam/Label?: ") :
+			     _("Sort Date/Frm/Recv/Subj/tO/Thread/Unsort/siZe/sCore/sPam/Label?: "),
+			     _("dfrsotuzcpl")))
   {
   case -1: /* abort - don't resort */
     return -1;
@@ -579,6 +579,10 @@ int mutt_select_sort (int reverse)
   case 10: /* s(p)am */
     Sort = SORT_SPAM;
     break;
+
+  case 11: /* (l)abel */
+    Sort = SORT_LABEL;
+    break;
   }
   if (reverse)
     Sort |= SORT_REVERSE;

copy.c

@@ -111,6 +111,10 @@ mutt_copy_hdr (FILE *in, FILE *out, LOFF_T off_start, LOFF_T off_end, int flags,
 	ignore = 0;
       }
 
+      if (flags & CH_UPDATE_LABEL &&
+	  mutt_strncasecmp ("X-Label:", buf, 8) == 0)
+	continue;
+
       if (!ignore && fputs (buf, out) == EOF)
 	return (-1);
     }
@@ -414,6 +418,15 @@ mutt_copy_header (FILE *in, HEADER *h, FILE *out, int flags, const char *prefix)
       fprintf (out, "Lines: %d\n", h->lines);
   }
 
+  if (flags & CH_UPDATE_LABEL && h->xlabel_changed)
+  {
+    h->xlabel_changed = 0;
+    if (h->env->x_label != NULL)
+      if (fprintf(out, "X-Label: %s\n", h->env->x_label) !=
+		  10 + strlen(h->env->x_label))
+        return -1;
+  }
+
   if ((flags & CH_NONEWLINE) == 0)
   {
     if (flags & CH_PREFIX)
@@ -494,6 +507,9 @@ _mutt_copy_message (FILE *fpout, FILE *fpin, HEADER *hdr, BODY *body,
       _mutt_make_string (prefix, sizeof (prefix), NONULL (Prefix), Context, hdr, 0);
   }
 
+  if (hdr->xlabel_changed)
+    chflags |= CH_UPDATE_LABEL;
+
   if ((flags & MUTT_CM_NOHEADER) == 0)
   {
     if (flags & MUTT_CM_PREFIX)

copy.h

@@ -53,6 +53,7 @@
 #define CH_UPDATE_IRT     (1<<16) /* update In-Reply-To: */
 #define CH_UPDATE_REFS    (1<<17) /* update References: */
 #define CH_DISPLAY        (1<<18) /* display result to user */
+#define CH_UPDATE_LABEL   (1<<19) /* update X-Label: from hdr->env->x_label? */
 
 
 int mutt_copy_hdr (FILE *, FILE *, LOFF_T, LOFF_T, int, const char *);

curs_main.c

@@ -2093,6 +2093,21 @@ int mutt_index_menu (void)
 	menu->redraw = REDRAW_FULL;
 	break;
 
+      case OP_EDIT_LABEL:
+
+	CHECK_MSGCOUNT;
+	CHECK_READONLY;
+	rc = mutt_label_message(tag ? NULL : CURHDR);
+	if (rc > 0) {
+	  Context->changed = 1;
+	  menu->redraw = REDRAW_FULL;
+	  mutt_message ("%d label%s changed.", rc, rc == 1 ? "" : "s");
+	}
+	else {
+	  mutt_message _("No labels changed.");
+	}
+	break;
+
       case OP_LIST_REPLY:
 
 	CHECK_ATTACH;

doc/manual.xml.head

@@ -6063,6 +6063,12 @@ not a standard message header field, but it can easily be inserted by
 procmail and other mail filtering agents.
 </para>
 
+<para>
+You can change or delete the <quote>X-Label:</quote> field within
+Mutt using the <quote>edit-label</quote> command, bound to the
+<quote>y</quote> key by default.  This works for tagged messages, too.
+</para>
+
 <para>
 Lastly, Mutt has the ability to <link linkend="sort">sort</link> the
 mailbox into <link linkend="threads">threads</link>.  A thread is a

functions.h

@@ -99,6 +99,7 @@ const struct binding_t OpMain[] = { /* map: index */
   { "delete-thread",		OP_DELETE_THREAD,		"\004" },
   { "delete-subthread",		OP_DELETE_SUBTHREAD,		"\033d" },
   { "edit",			OP_EDIT_MESSAGE,		"e" },
+  { "edit-label",		OP_EDIT_LABEL,			"y" },
   { "edit-type",		OP_EDIT_TYPE,			"\005" },
   { "forward-message",		OP_FORWARD_MESSAGE,		"f" },
   { "flag-message",		OP_FLAG_MESSAGE,		"F" },
@@ -200,6 +201,7 @@ const struct binding_t OpPager[] = { /* map: pager */
   { "set-flag",  	OP_MAIN_SET_FLAG,		"w" },
   { "clear-flag",       OP_MAIN_CLEAR_FLAG,		"W" },
   { "edit",		OP_EDIT_MESSAGE,		"e" },
+  { "edit-label",	OP_EDIT_LABEL,			"y" },
   { "edit-type",	OP_EDIT_TYPE,			"\005" },
   { "forward-message",	OP_FORWARD_MESSAGE,		"f" },
   { "flag-message",	OP_FLAG_MESSAGE,		"F" },

headers.c

@@ -211,3 +211,61 @@ void mutt_edit_headers (const char *editor,
     }
   }
 }
+
+/*
+ * add an X-Label: field.
+ */
+static int label_message(HEADER *hdr, char *new)
+{
+  if (hdr == NULL)
+    return 0;
+  if (hdr->env->x_label == NULL && new == NULL)
+    return 0;
+  if (hdr->env->x_label != NULL && new != NULL &&
+      strcmp(hdr->env->x_label, new) == 0)
+    return 0;
+  if (hdr->env->x_label != NULL)
+    FREE(&hdr->env->x_label);
+  if (new == NULL)
+    hdr->env->x_label = NULL;
+  else
+    hdr->env->x_label = safe_strdup(new);
+  return hdr->changed = hdr->xlabel_changed = 1;
+}
+
+int mutt_label_message(HEADER *hdr)
+{
+  char buf[LONG_STRING], *new;
+  int i;
+  int changed;
+
+  *buf = '\0';
+  if (hdr != NULL && hdr->env->x_label != NULL) {
+    strncpy(buf, hdr->env->x_label, LONG_STRING);
+  }
+
+  if (mutt_get_field("Label: ", buf, sizeof(buf), 0 /* | MUTT_CLEAR */) != 0)
+    return 0;
+
+  new = buf;
+  SKIPWS(new);
+  if (*new == '\0')
+    new = NULL;
+
+  changed = 0;
+  if (hdr != NULL) {
+    changed += label_message(hdr, new);
+  } else {
+#define HDR_OF(index) Context->hdrs[Context->v2r[(index)]]
+    for (i = 0; i < Context->vcount; ++i) {
+      if (HDR_OF(i)->tagged)
+        if (label_message(HDR_OF(i), new)) {
+          ++changed;
+          mutt_set_flag(Context, HDR_OF(i),
+            MUTT_TAG, 0);
+        }
+    }
+  }
+
+  return changed;
+}

imap/imap.c

@@ -1242,7 +1242,7 @@ int imap_sync_mailbox (CONTEXT* ctx, int expunge, int* index_hint)
        * we delete the message and reupload it.
        * This works better if we're expunging, of course. */
       if ((h->env && (h->env->refs_changed || h->env->irt_changed)) ||
-	  h->attach_del)
+	  h->attach_del || h->xlabel_changed)
       {
         mutt_message (_("Saving changed messages... [%d/%d]"), n+1,
                       ctx->msgcount);
@@ -1252,6 +1252,7 @@ int imap_sync_mailbox (CONTEXT* ctx, int expunge, int* index_hint)
 	  dprint (1, (debugfile, "imap_sync_mailbox: Error opening mailbox in append mode\n"));
 	else
 	  _mutt_save_message (h, appendctx, 1, 0, 0);
+	h->xlabel_changed = 0;
       }
     }
   }

init.h

@@ -3813,6 +3813,7 @@ const struct mapping_t SortMethods[] = {
   { "to",		SORT_TO },
   { "score",		SORT_SCORE },
   { "spam",		SORT_SPAM },
+  { "label",		SORT_LABEL },
   { NULL,               0 }
 };
 
@@ -3832,6 +3833,7 @@ const struct mapping_t SortAuxMethods[] = {
   { "to",		SORT_TO },
   { "score",		SORT_SCORE },
   { "spam",		SORT_SPAM },
+  { "label",		SORT_LABEL },
   { NULL,               0 }
 };
 

mh.c

@@ -1793,7 +1793,7 @@ static int mh_sync_message (CONTEXT * ctx, int msgno)
 {
   HEADER *h = ctx->hdrs[msgno];
 
-  if (h->attach_del || 
+  if (h->attach_del || h->xlabel_changed ||
       (h->env && (h->env->refs_changed || h->env->irt_changed)))
     if (mh_rewrite_message (ctx, msgno) != 0)
       return -1;
@@ -1805,7 +1805,7 @@ static int maildir_sync_message (CONTEXT * ctx, int msgno)
 {
   HEADER *h = ctx->hdrs[msgno];
 
-  if (h->attach_del || 
+  if (h->attach_del || h->xlabel_changed ||
       (h->env && (h->env->refs_changed || h->env->irt_changed)))
   {
     /* when doing attachment deletion/rethreading, fall back to the MH case. */
@@ -1927,6 +1927,7 @@ int mh_sync_mailbox (CONTEXT * ctx, int *index_hint)
       }
     }
     else if (ctx->hdrs[i]->changed || ctx->hdrs[i]->attach_del ||
+	     ctx->hdrs[i]->xlabel_changed ||
 	     (ctx->magic == MUTT_MAILDIR
 	      && (option (OPTMAILDIRTRASH) || ctx->hdrs[i]->trash)
 	      && (ctx->hdrs[i]->deleted != ctx->hdrs[i]->trash)))

mutt.h

@@ -760,6 +760,7 @@ typedef struct header
 					 * This flag is used by the maildir_trash
 					 * option.
 					 */
+  unsigned int xlabel_changed : 1;	/* editable - used for syncing */
   
   /* timezone of the sender of this message */
   unsigned int zhours : 5;

pager.c

@@ -2814,6 +2814,18 @@ search_next:
 	redraw = REDRAW_FULL;
 	break;
 
+     case OP_EDIT_LABEL:
+        CHECK_MODE(IsHeader (extra));
+        rc = mutt_label_message(extra->hdr);
+        if (rc > 0) {
+          Context->changed = 1;
+          redraw = REDRAW_FULL;
+          mutt_message ("%d label%s changed.", rc, rc == 1 ? "" : "s");
+        }
+        else {
+          mutt_message _("No labels changed.");
+        }
+        break;
 
       case OP_MAIL_KEY:
         if (!(WithCrypto & APPLICATION_PGP))

protos.h

@@ -186,6 +186,7 @@ void mutt_edit_content_type (HEADER *, BODY *, FILE *);
 void mutt_edit_file (const char *, const char *);
 void mutt_edit_headers (const char *, const char *, HEADER *, char *, size_t);
 int mutt_filter_unprintable (char **);
+int mutt_label_message (HEADER *);
 void mutt_curses_error (const char *, ...);
 void mutt_curses_message (const char *, ...);
 void mutt_encode_descriptions (BODY *, short);

sort.c

@@ -210,6 +210,36 @@ static int compare_spam (const void *a, const void *b)
   return (SORTCODE(result));
 }
 
+int compare_label (const void *a, const void *b)
+{
+  HEADER **ppa = (HEADER **) a;
+  HEADER **ppb = (HEADER **) b;
+  int     ahas, bhas, result = 0;
+
+  /* As with compare_spam, not all messages will have the x-label
+   * property.  Blank X-Labels are treated as null in the index
+   * display, so we'll consider them as null for sort, too.       */
+  ahas = (*ppa)->env && (*ppa)->env->x_label && *((*ppa)->env->x_label);
+  bhas = (*ppb)->env && (*ppb)->env->x_label && *((*ppb)->env->x_label);
+
+  /* First we bias toward a message with a label, if the other does not. */
+  if (ahas && !bhas)
+    return (SORTCODE(-1));
+  if (!ahas && bhas)
+    return (SORTCODE(1));
+
+  /* If neither has a label, use aux sort. */
+  if (!ahas && !bhas)
+  {
+    AUXSORT(result, a, b);
+    return (SORTCODE(result));
+  }
+
+  /* If both have a label, we just do a lexical compare. */
+  result = mutt_strcasecmp((*ppa)->env->x_label, (*ppb)->env->x_label);
+  return (SORTCODE(result));
+}
+
 sort_t *mutt_get_sort_func (int method)
 {
   switch (method & SORT_MASK)
@@ -232,6 +262,8 @@ sort_t *mutt_get_sort_func (int method)
       return (compare_score);
     case SORT_SPAM:
       return (compare_spam);
+    case SORT_LABEL:
+      return (compare_label);
     default:
       return (NULL);
   }

sort.h

@@ -35,6 +35,7 @@
 #define SORT_UNREAD	16
 #define SORT_FLAGGED	17
 #define SORT_PATH	18
+#define SORT_LABEL	19
 
 /* Sort and sort_aux are shorts, and are a composite of a
  * constant sort operation number and a set of compounded