This patch is ugly hack to c-client adds OR criteria from IMAP4 spec to search string passed to mail_criteria().
Note that parentheses syntax is not implemented.
--- imap-2007f-orig/src/c-client/mail.c	2013-01-23 17:10:23.000000000 +0200
+++ imap-2007f/src/c-client/mail.c	2013-01-25 18:19:04.000000000 +0200
@@ -3990,24 +3990,56 @@
   }
   return NIL;
 }
+
+
+SEARCHPGM *mail_criteria_fixed (char *criteria, int *skip);
+
+static int mail_criteria_or(SEARCHOR **orpgm, char **r) {
+
+  char tmp[MAILTMPLEN], *pr;
+  int skip = 1;                                 /* set mail_criteria_fixed to do one run from a loop only */ 
+
+  pr = *r;                                      /* save original pointer to reset in case of error */
+
+  while (*orpgm) orpgm = &(*orpgm)->next;       /* find tail of list */
+  *orpgm = mail_newsearchor ();                 /* make new entry */
+
+  (*orpgm)->first = mail_criteria_fixed(*r, &skip);
+/*  if ( !(*orpgm)->first ) return NIL; // FIXME: does not work ? */
+  *r = *r+skip;                                 /* update original criteria with processed tokens */
+
+  (*orpgm)->second = mail_criteria_fixed(*r, &skip);
+/*  if ( !(*orpgm)->first ) { *r = pr; return NIL; } // FIXME: does not work ? */
+  *r = *r+skip;
+
+  return T;
+}
+
+
 
 /* Mail parse search criteria
- * Accepts: criteria
+ * [DG]: fixed for OR criterion by recursive calling:
+ * Accepts: criteria, skip
+ *   "skip" - do one run only when set and updated with offset of chars parsed
  * Returns: search program if parse successful, else NIL
  */
 
-SEARCHPGM *mail_criteria (char *criteria)
+SEARCHPGM *mail_criteria_fixed (char *criteria, int *skip)
 {
   SEARCHPGM *pgm = NIL;
-  char *criterion,*r,tmp[MAILTMPLEN];
-  int f;
+  char *criterion,*r,tmp[MAILTMPLEN],*pr;
+  int f, fcount=0;
   if (criteria) {		/* only if criteria defined */
-				/* make writeable copy of criteria */
-    criteria = cpystr (criteria);
+
+    criteria = cpystr (criteria); /* make writeable copy of criteria */
+
+    pr = criteria; /* save original criteria's start to calculate difference */
+
 				/* for each criterion */
     for (pgm = mail_newsearchpgm (), criterion = strtok_r (criteria," ",&r);
 	 criterion; (criterion = strtok_r (NIL," ",&r))) {
       f = NIL;			/* init then scan the criterion */
+
       switch (*ucase (criterion)) {
       case 'A':			/* possible ALL, ANSWERED */
 	if (!strcmp (criterion+1,"LL")) f = T;
@@ -4036,12 +4068,13 @@
 	if (!strcmp (criterion+1,"EYWORD"))
 	  f = mail_criteria_string (&pgm->keyword,&r);
 	break;
-
       case 'N':			/* possible NEW */
 	if (!strcmp (criterion+1,"EW")) f = pgm->recent = pgm->unseen = T;
 	break;
       case 'O':			/* possible OLD, ON */
 	if (!strcmp (criterion+1,"LD")) f = pgm->old = T;
+        else if (!strcmp (criterion+1,"R"))    /* [DG]: OR is possible in this patch */
+	  f = mail_criteria_or (&pgm->or,&r);
 	else if (!strcmp (criterion+1,"N"))
 	  f = mail_criteria_date (&pgm->on,&r);
 	break;
@@ -4066,6 +4099,7 @@
 	  if (!strcmp (criterion+2,"ANSWERED")) f = pgm->unanswered = T;
 	  else if (!strcmp (criterion+2,"DELETED")) f = pgm->undeleted = T;
 	  else if (!strcmp (criterion+2,"FLAGGED")) f = pgm->unflagged = T;
+	  else if (!strcmp (criterion+2,"DRAFT")) f = pgm->undraft = T;
 	  else if (!strcmp (criterion+2,"KEYWORD"))
 	    f = mail_criteria_string (&pgm->unkeyword,&r);
 	  else if (!strcmp (criterion+2,"SEEN")) f = pgm->unseen = T;
@@ -4080,12 +4114,26 @@
 	mail_free_searchpgm (&pgm);
 	break;
       }
+      fcount++;                         /* count rounds */
+      if ( *skip && fcount == 1 ) {     /* */
+        (*skip) = r - pr;
+        break;
+      }
     }
 				/* no longer need copy of criteria */
     fs_give ((void **) &criteria);
   }
   return pgm;
 }
+
+/* [DG]: this is wrapper over original function ot add additional arg */
+SEARCHPGM *mail_criteria (char *criteria)
+{
+  int skip = 0;
+  return mail_criteria_fixed (criteria, &skip);
+
+}
+
 
 /* Parse a date
  * Accepts: pointer to date integer to return