imap4d: implement SEARCH CHARSET; fix BODY and TEXT searches.

* imap4d/search.c: Implement proper BODY searches. Implement CHARSET.
* imap4d/util.c (util_strcasestr): Remove. Use mu_c_strcasestr instead.
* imap4d/imap4d.h: Likewise.
* NEWS: Document changes.

5 files changed, 341 insertions, 141 deletions

diff --git a/NEWS b/NEWS
index 84d36010c..4f5c0dec9 100644
--- a/NEWS
+++ b/NEWS
@@ -1,2 +1,2 @@
-GNU mailutils NEWS -- history of user-visible changes. 2019-01-23
+GNU mailutils NEWS -- history of user-visible changes. 2019-01-26
 Copyright (C) 2002-2019 Free Software Foundation, Inc.
@@ -8,2 +8,11 @@ Version 3.5.90 (git)
 
+* imap4d: SEARCH command
+
+** Implemented SEARCH CHARSET
+
+** Improved SEARCH BODY and SEARCH TEXT commands
+
+Both commands now properly descend into multipart message parts and
+decode messages, if necessary
+
 * Fixes in the 'mail' utility
diff --git a/imap4d/imap4d.h b/imap4d/imap4d.h
index 2ad339a30..b90d653a0 100644
--- a/imap4d/imap4d.h
+++ b/imap4d/imap4d.h
@@ -456,3 +456,2 @@ extern int util_parse_ctime_date (const char *date, time_t *timep,
 				  enum datetime_parse_mode flag);
-extern char *util_strcasestr (const char *haystack, const char *needle);
 extern char *util_localname (void);
diff --git a/imap4d/search.c b/imap4d/search.c
index 1d28b570f..3c243eddf 100644
--- a/imap4d/search.c
+++ b/imap4d/search.c
@@ -17,2 +17,3 @@
 #include "imap4d.h"
+#include <mailutils/assoc.h>
 
@@ -92,3 +93,3 @@ struct search_node
 static void cond_msgset (struct parsebuf *, struct search_node *,
-			 struct value *, struct value *);       
+			 struct value *, struct value *);
 static void cond_bcc (struct parsebuf *, struct search_node *,
@@ -96,21 +97,21 @@ static void cond_bcc (struct parsebuf *, struct search_node *,
 static void cond_before (struct parsebuf *, struct search_node *,
-			 struct value *, struct value *);     
+			 struct value *, struct value *);
 static void cond_body (struct parsebuf *, struct search_node *,
-		       struct value *, struct value *);       
+		       struct value *, struct value *);
 static void cond_cc (struct parsebuf *, struct search_node *,
-		     struct value *, struct value *);        
+		     struct value *, struct value *);
 static void cond_from (struct parsebuf *, struct search_node *,
-		       struct value *, struct value *);     
+		       struct value *, struct value *);
 static void cond_header (struct parsebuf *, struct search_node *,
-			 struct value *, struct value *);      
+			 struct value *, struct value *);
 static void cond_keyword (struct parsebuf *, struct search_node *,
-			  struct value *, struct value *);   
+			  struct value *, struct value *);
 static void cond_larger (struct parsebuf *, struct search_node *,
-			 struct value *, struct value *);   
+			 struct value *, struct value *);
 static void cond_on (struct parsebuf *, struct search_node *,
-		     struct value *, struct value *);         
+		     struct value *, struct value *);
 static void cond_sentbefore (struct parsebuf *, struct search_node *,
-			     struct value *, struct value *); 
+			     struct value *, struct value *);
 static void cond_senton (struct parsebuf *, struct search_node *,
-			 struct value *, struct value *);     
+			 struct value *, struct value *);
 static void cond_sentsince (struct parsebuf *, struct search_node *,
@@ -118,13 +119,13 @@ static void cond_sentsince (struct parsebuf *, struct search_node *,
 static void cond_since (struct parsebuf *, struct search_node *,
-			struct value *, struct value *);      
+			struct value *, struct value *);
 static void cond_smaller (struct parsebuf *, struct search_node *,
-			  struct value *, struct value *);    
+			  struct value *, struct value *);
 static void cond_subject (struct parsebuf *, struct search_node *,
-			  struct value *, struct value *);  
+			  struct value *, struct value *);
 static void cond_text (struct parsebuf *, struct search_node *,
-		       struct value *, struct value *);       
+		       struct value *, struct value *);
 static void cond_to (struct parsebuf *, struct search_node *,
-		     struct value *, struct value *);      
+		     struct value *, struct value *);
 static void cond_uid (struct parsebuf *, struct search_node *,
-		      struct value *, struct value *);   
+		      struct value *, struct value *);
 
@@ -140,3 +141,3 @@ struct cond
 /* Types are: s -- string
-              n -- number
+	      n -- number
 	      d -- date
@@ -215,3 +216,3 @@ struct mem_chain
    that they are enclosed in doublequotes */
-#define MAXTOKEN 64 
+#define MAXTOKEN 64
 
@@ -220,14 +221,15 @@ struct parsebuf
 {
-  imap4d_tokbuf_t tok;          /* Token buffer */   
+  imap4d_tokbuf_t tok;          /* Token buffer */
   int arg;                      /* Argument number */
   char *token;                  /* Current token */
-  int isuid;                    /* UIDs instead of msgnos are required */ 
+  int isuid;                    /* UIDs instead of msgnos are required */
   char *err_mesg;               /* Error message if a parse error occured */
   struct mem_chain *alloc;      /* Chain of objects allocated during parsing */
-  
+  char *charset;                /* Charset, other than US-ASCII requested */
+
   struct search_node *tree;     /* Parse tree */
-  
-                                /* Execution time only: */
+
+				/* Execution time only: */
   size_t msgno;                 /* Number of current message */
-  mu_message_t msg;             /* Current message */ 
+  mu_message_t msg;             /* Current message */
 };
@@ -243,2 +245,3 @@ static int search_run (struct parsebuf *pb);
 static void do_search (struct parsebuf *pb);
+static int available_charset (const char *charset);
 
@@ -248,3 +251,3 @@ static void do_search (struct parsebuf *pb);
    Arguments:  OPTIONAL [CHARSET] specification
-               searching criteria (one or more)
+	       searching criteria (one or more)
 
@@ -253,5 +256,5 @@ static void do_search (struct parsebuf *pb);
    Result:     OK - search completed
-               NO - search error: can't search that [CHARSET] or
-                    criteria
-               BAD - command unknown or arguments invalid
+	       NO - search error: can't search that [CHARSET] or
+		    criteria
+	       BAD - command unknown or arguments invalid
 */
@@ -260,3 +263,3 @@ int
 imap4d_search (struct imap4d_session *session,
-               struct imap4d_command *command, imap4d_tokbuf_t tok)
+	       struct imap4d_command *command, imap4d_tokbuf_t tok)
 {
@@ -264,3 +267,3 @@ imap4d_search (struct imap4d_session *session,
   char *err_text= "";
-  
+
   rc = imap4d_search0 (tok, 0, &err_text);
@@ -268,3 +271,3 @@ imap4d_search (struct imap4d_session *session,
 }
-  
+
 int
@@ -273,3 +276,3 @@ imap4d_search0 (imap4d_tokbuf_t tok, int isuid, char **err_text)
   struct parsebuf parsebuf;
-  
+
   memset (&parsebuf, 0, sizeof(parsebuf));
@@ -286,3 +289,3 @@ imap4d_search0 (imap4d_tokbuf_t tok, int isuid, char **err_text)
     }
-  
+
   if (mu_c_strcasecmp (parsebuf.token, "CHARSET") == 0)
@@ -298,5 +301,11 @@ imap4d_search0 (imap4d_tokbuf_t tok, int isuid, char **err_text)
 	{
-	  *err_text = "Charset not supported";
-	  return RESP_NO;
+	  parsebuf.charset = parse_strdup (&parsebuf, parsebuf.token);
+	  if (!available_charset (parsebuf.charset))
+	    {
+	      *err_text = "[BADCHARSET] Charset not supported";
+	      return RESP_NO;
+	    }
 	}
+      else
+	parsebuf.charset = NULL;
 
@@ -307,3 +316,2 @@ imap4d_search0 (imap4d_tokbuf_t tok, int isuid, char **err_text)
 	}
-
     }
@@ -325,8 +333,8 @@ imap4d_search0 (imap4d_tokbuf_t tok, int isuid, char **err_text)
     }
-  
+
   /* Execute compiled expression */
   do_search (&parsebuf);
-  
+
   parse_free_mem (&parsebuf);
-  
+
   *err_text = "Completed";
@@ -341,3 +349,3 @@ do_search (struct parsebuf *pb)
   size_t count = 0;
-  
+
   mu_mailbox_messages_count (mbox, &count);
@@ -419,3 +427,3 @@ parse_alloc (struct parsebuf *pb, size_t size)
 
-/* Create a copy of the string. */ 
+/* Create a copy of the string. */
 char *
@@ -447,3 +455,3 @@ parse_msgset_create (struct parsebuf *pb, mu_mailbox_t mbox, int flags)
    search_key_list : search_key
-	           | search_key_list search_key
+		   | search_key_list search_key
 		   ;
@@ -451,3 +459,3 @@ parse_msgset_create (struct parsebuf *pb, mu_mailbox_t mbox, int flags)
    search_key      : simple_key
-	           | NOT simple_key
+		   | NOT simple_key
 		   | OR simple_key simple_key
@@ -488,3 +496,3 @@ parse_search_key (struct parsebuf *pb)
   struct search_node *node;
-  
+
   if (strcmp (pb->token, "(") == 0)
@@ -493,3 +501,3 @@ parse_search_key (struct parsebuf *pb)
 	return NULL;
-      
+
       node = parse_search_key_list (pb);
@@ -497,3 +505,3 @@ parse_search_key (struct parsebuf *pb)
 	return NULL;
-      
+
       if (strcmp (pb->token, ")"))
@@ -583,3 +591,3 @@ parse_equiv_key (struct parsebuf *pb)
 		       __FILE__, __LINE__);
-      abort (); 
+      abort ();
     }
@@ -603,3 +611,3 @@ parse_simple_key (struct parsebuf *pb)
     ;
-  
+
   if (!condp->name)
@@ -607,6 +615,6 @@ parse_simple_key (struct parsebuf *pb)
       mu_msgset_t msgset = parse_msgset_create (pb, mbox, MU_MSGSET_NUM);
-      
+
       if (mu_msgset_parse_imap (msgset,
 				pb->isuid ? MU_MSGSET_UID : MU_MSGSET_NUM,
-				pb->token, NULL) == 0) 
+				pb->token, NULL) == 0)
 	{
@@ -616,3 +624,3 @@ parse_simple_key (struct parsebuf *pb)
 	  np->v.value.v.msgset = msgset;
-	  
+
 	  node = parse_alloc (pb, sizeof *node);
@@ -623,5 +631,5 @@ parse_simple_key (struct parsebuf *pb)
 	  node->v.key.fun = cond_msgset;
-	  
+
 	  parse_gettoken (pb, 0);
-	  
+
 	  return node;
@@ -634,3 +642,3 @@ parse_simple_key (struct parsebuf *pb)
     }
-  
+
   node = parse_alloc (pb, sizeof *node);
@@ -640,3 +648,3 @@ parse_simple_key (struct parsebuf *pb)
   node->v.key.narg = 0;
-  
+
   parse_gettoken (pb, 0);
@@ -648,3 +656,3 @@ parse_simple_key (struct parsebuf *pb)
       struct search_node *arg;
-      
+
       for (; *t; t++, parse_gettoken (pb, 0))
@@ -656,3 +664,3 @@ parse_simple_key (struct parsebuf *pb)
 	    }
-	  
+
 	  if (!pb->token)
@@ -662,3 +670,3 @@ parse_simple_key (struct parsebuf *pb)
 	    }
-	  
+
 	  arg = parse_alloc (pb, sizeof *arg);
@@ -671,3 +679,3 @@ parse_simple_key (struct parsebuf *pb)
 	      break;
-	      
+
 	    case 'n': /* number */
@@ -682,3 +690,3 @@ parse_simple_key (struct parsebuf *pb)
 	      break;
-	      
+
 	    case 'd': /* date */
@@ -693,3 +701,3 @@ parse_simple_key (struct parsebuf *pb)
 	      break;
-	      
+
 	    case 'u': /* UID message set */
@@ -699,3 +707,3 @@ parse_simple_key (struct parsebuf *pb)
 	      if (mu_msgset_parse_imap (arg->v.value.v.msgset, MU_MSGSET_UID,
-					pb->token, NULL)) 
+					pb->token, NULL))
 		{
@@ -705,3 +713,3 @@ parse_simple_key (struct parsebuf *pb)
 	      break;
-	      
+
 	    default:
@@ -713,3 +721,3 @@ parse_simple_key (struct parsebuf *pb)
 	  node->v.key.arg[node->v.key.narg++] = arg;
-	}  
+	}
     }
@@ -725,3 +733,3 @@ evaluate_node (struct search_node *node, struct parsebuf *pb,
   struct value argval[MAX_NODE_ARGS];
-  
+
   switch (node->type)
@@ -735,3 +743,3 @@ evaluate_node (struct search_node *node, struct parsebuf *pb,
 	}
-      
+
       node->v.key.fun (pb, node, argval, val);
@@ -750,3 +758,3 @@ evaluate_node (struct search_node *node, struct parsebuf *pb,
       break;
-      
+
     case node_or:
@@ -768,3 +776,3 @@ evaluate_node (struct search_node *node, struct parsebuf *pb,
       break;
-      
+
     case node_value:
@@ -798,11 +806,34 @@ _scan_header (struct parsebuf *pb, char *name, char *value)
 {
-  const char *hval;
+  char *hval;
   mu_header_t header = NULL;
-  
+  int i, rc;
+  int result = 0;
+
   mu_message_get_header (pb->msg, &header);
-  if (mu_header_sget_value (header, name, &hval) == 0)
+
+  for (i = 1;
+       result == 0
+	 && (rc = mu_header_aget_value_unfold_n (header, name, i, &hval)) == 0;
+       i++)
     {
-      return util_strcasestr (hval, value) != NULL;
+      if (pb->charset)
+	{
+	  char *tmp;
+	  rc = mu_rfc2047_decode (pb->charset, hval, &tmp);
+	  if (rc)
+	    {
+	      mu_diag_funcall (MU_DIAG_ERR, "mu_rfc2047_decode", hval, rc);
+	      free (hval);
+	      continue;
+	    }
+	  free (hval);
+	  hval = tmp;
+	}
+      result = mu_c_strcasestr (hval, value) != NULL;
+      free (hval);
     }
-  return 0;
+  if (!(rc == 0 || rc == MU_ERR_NOENT))
+    mu_diag_funcall (MU_DIAG_ERR, "mu_header_aget_value_unfold_n", NULL, rc);
+
+  return result;
 }
@@ -815,3 +846,3 @@ _header_date (struct parsebuf *pb, time_t *timep)
   mu_header_t header = NULL;
-  
+
   mu_message_get_header (pb->msg, &header);
@@ -827,3 +858,2 @@ _scan_header_all (struct parsebuf *pb, char *text)
 {
-  const char *hval;
   mu_header_t header = NULL;
@@ -831,2 +861,3 @@ _scan_header_all (struct parsebuf *pb, char *text)
   int i, rc;
+  int result;
 
@@ -834,38 +865,183 @@ _scan_header_all (struct parsebuf *pb, char *text)
   mu_header_get_field_count (header, &fcount);
-  for (i = rc = 0; i < fcount; i++)
+  result = 0;
+  for (i = 1; result == 0 && i < fcount; i++)
     {
-      if (mu_header_sget_field_value (header, i, &hval) == 0)
-	rc = util_strcasestr (hval, text) != NULL;
+      char *hval;
+
+      rc = mu_header_aget_field_value_unfold (header, i, &hval);
+      if (rc)
+	{
+	  mu_diag_funcall (MU_DIAG_ERR, "mu_header_aget_field_value_unfold",
+			   NULL, rc);
+	  continue;
+	}
+
+      if (pb->charset)
+	{
+	  char *tmp;
+	  rc = mu_rfc2047_decode (pb->charset, hval, &tmp);
+	  if (rc)
+	    {
+	      mu_diag_funcall (MU_DIAG_ERR, "mu_rfc2047_decode", hval, rc);
+	      free (hval);
+	      continue;
+	    }
+
+	  free (hval);
+	  hval = tmp;
+	}
+       result = mu_c_strcasestr (hval, text) != NULL;
+       free (hval);
     }
-  return rc;
+  return result;
 }
-
-/* Scan body of the message for the occurrence of a substring */
-/* FIXME: The algorithm below is broken */
+
 static int
-_scan_body (struct parsebuf *pb, char *text)
+_match_text (struct parsebuf *pb, mu_message_t msg, mu_content_type_t ct,
+	     char const *encoding,
+	     char *text)
 {
-  mu_body_t body = NULL;
-  mu_stream_t stream = NULL;
-  size_t size = 0, lines = 0;
-  char buffer[128];
-  size_t n = 0;
+  mu_body_t body;
+  mu_stream_t str;
   int rc;
-  
-  mu_message_get_body (pb->msg, &body);
-  mu_body_size (body, &size);
-  mu_body_lines (body, &lines);
-  mu_body_get_streamref (body, &stream);
-  rc = 0;
-  while (rc == 0
-	 && mu_stream_read (stream, buffer, sizeof(buffer)-1, &n) == 0
+  int result;
+  char *buffer = NULL;
+  size_t bufsize = 0;
+  size_t n;
+
+  mu_message_get_body (msg, &body);
+  mu_body_get_streamref (body, &str);
+
+  if (encoding)
+    {
+      mu_stream_t flt;
+      rc = mu_filter_create (&flt, str, encoding,
+			     MU_FILTER_DECODE,
+			     MU_STREAM_READ);
+      mu_stream_unref (str);
+      if (rc)
+	{
+	  mu_error (_("can't handle encoding %s: %s"),
+		    encoding, mu_strerror (rc));
+	  return 0;
+	}
+      str = flt;
+    }
+
+  if (pb->charset)
+    {
+      struct mu_mime_param *param;
+      if (mu_assoc_lookup (ct->param, "charset", &param) == 0
+	  && mu_c_strcasecmp (param->value, pb->charset))
+	{
+	  char const *argv[] = { "iconv", NULL, NULL, NULL };
+	  mu_stream_t flt;
+
+	  argv[1] = param->value;
+	  argv[2] = pb->charset;
+	  rc = mu_filter_chain_create (&flt, str,
+				       MU_FILTER_ENCODE,
+				       MU_STREAM_READ,
+				       MU_ARRAY_SIZE (argv) - 1,
+				       (char**) argv);
+	  mu_stream_unref (str);
+	  if (rc)
+	    {
+	      mu_error (_("can't convert from charset %s to %s"),
+			param->value, pb->charset);
+	      return 0;
+	    }
+	  str = flt;
+	}
+    }
+
+  result = 0;
+  while ((rc = mu_stream_getline (str, &buffer, &bufsize, &n)) == 0
 	 && n > 0)
     {
-      buffer[n] = 0;
-      rc = util_strcasestr (buffer, text) != NULL;
+      result = mu_c_strcasestr (buffer, text) != NULL;
+      if (result)
+	break;
     }
-  mu_stream_destroy (&stream);
-  return rc;
+  mu_stream_destroy (&str);
+  if (rc)
+    mu_diag_funcall (MU_DIAG_ERR, "mu_stream_getline", NULL, rc);
+  return result;
 }
 
+static int
+_match_multipart (struct parsebuf *pb, mu_message_t msg, char *text)
+{
+  mu_header_t hdr;
+  char *encoding;
+  int ismp;
+  int result;
+  mu_content_type_t ct;
+  char *buf;
+  int rc;
+
+  if (mu_message_is_multipart (msg, &ismp))
+    return 0;
+  if (mu_message_get_header (msg, &hdr))
+    return 0;
+
+  if (mu_header_aget_value_unfold (hdr, MU_HEADER_CONTENT_TYPE, &buf))
+    {
+      buf = strdup ("text/plain");
+      if (!buf)
+	return 0;
+    }
+  rc = mu_content_type_parse (buf, NULL, &ct);
+  free (buf);
+  if (rc)
+    return 0;
+
+  if (mu_header_aget_value_unfold (hdr, MU_HEADER_CONTENT_TRANSFER_ENCODING,
+				   &encoding))
+    encoding = NULL;
+
+  if (ismp)
+    {
+      size_t i, nparts;
+
+      mu_message_get_num_parts (msg, &nparts);
+
+      for (i = 1; i <= nparts; i++)
+	{
+	  mu_message_t submsg = NULL;
+
+	  if (mu_message_get_part (msg, i, &submsg) == 0)
+	    {
+	      result = _match_multipart (pb, submsg, text);
+	      if (result)
+		break;
+	    }
+	}
+    }
+  else if (mu_c_strcasecmp (ct->type, "message") == 0
+	   && mu_c_strcasecmp (ct->subtype, "rfc822") == 0)
+    {
+      mu_message_t submsg = NULL;
+
+      if (mu_message_unencapsulate (msg, &submsg, NULL) == 0)
+	{
+	  result = _match_multipart (pb, submsg, text);
+	}
+    }
+  else if (mu_c_strcasecmp (ct->type, "text") == 0)
+    result = _match_text (pb, msg, ct, encoding, text);
+
+  free (encoding);
+  mu_content_type_destroy (&ct);
+
+  return result;
+}
+
+/* Scan body of the message for the occurrence of a substring */
+static int
+_scan_body (struct parsebuf *pb, char *text)
+{
+  return _match_multipart (pb, pb->msg, text);
+}
+
 /* Basic instructions */
@@ -887,3 +1063,3 @@ cond_bcc (struct parsebuf *pb, struct search_node *node, struct value *arg,
   retval->v.number = _scan_header (pb, MU_HEADER_BCC, arg[0].v.string);
-}                      
+}
 
@@ -897,3 +1073,3 @@ cond_before (struct parsebuf *pb, struct search_node *node, struct value *arg,
   mu_envelope_t env;
-  
+
   mu_message_get_envelope (pb->msg, &env);
@@ -907,3 +1083,3 @@ cond_before (struct parsebuf *pb, struct search_node *node, struct value *arg,
     }
-}                   
+}
 
@@ -915,3 +1091,3 @@ cond_body (struct parsebuf *pb, struct search_node *node, struct value *arg,
   retval->v.number = _scan_body (pb, arg[0].v.string);
-}                     
+}
 
@@ -923,3 +1099,3 @@ cond_cc (struct parsebuf *pb, struct search_node *node, struct value *arg,
   retval->v.number = _scan_header (pb, MU_HEADER_CC, arg[0].v.string);
-}                       
+}
 
@@ -933,10 +1109,10 @@ cond_from (struct parsebuf *pb, struct search_node *node, struct value *arg,
   int rc = 0;
-  
+
   mu_message_get_envelope (pb->msg, &env);
   if (mu_envelope_sget_sender (env, &from) == 0)
-    rc = util_strcasestr (from, s) != NULL;
-  
+    rc = mu_c_strcasestr (from, s) != NULL;
+
   retval->type = value_number;
   retval->v.number = rc || _scan_header (pb, MU_HEADER_FROM, s);
-}                     
+}
 
@@ -951,3 +1127,3 @@ cond_header (struct parsebuf *pb, struct search_node *node, struct value *arg,
   retval->v.number = _scan_header (pb, name, value);
-}                   
+}
 
@@ -959,3 +1135,3 @@ cond_keyword (struct parsebuf *pb, struct search_node *node, struct value *arg,
   mu_attribute_t attr = NULL;
-  
+
   mu_message_get_attribute (pb->msg, &attr);
@@ -963,3 +1139,3 @@ cond_keyword (struct parsebuf *pb, struct search_node *node, struct value *arg,
   retval->v.number = util_attribute_matches_flag (attr, s);
-}                  
+}
 
@@ -970,3 +1146,3 @@ cond_larger (struct parsebuf *pb, struct search_node *node, struct value *arg,
   size_t size = 0;
-  
+
   mu_message_size (pb->msg, &size);
@@ -974,3 +1150,3 @@ cond_larger (struct parsebuf *pb, struct search_node *node, struct value *arg,
   retval->v.number = size > arg[0].v.number;
-}                   
+}
 
@@ -984,3 +1160,3 @@ cond_on (struct parsebuf *pb, struct search_node *node, struct value *arg,
   mu_envelope_t env;
-  
+
   mu_message_get_envelope (pb->msg, &env);
@@ -994,3 +1170,3 @@ cond_on (struct parsebuf *pb, struct search_node *node, struct value *arg,
     }
-}                       
+}
 
@@ -1007,3 +1183,3 @@ cond_sentbefore (struct parsebuf *pb, struct search_node *node,
   retval->v.number = mesg_time < t;
-}               
+}
 
@@ -1019,3 +1195,3 @@ cond_senton (struct parsebuf *pb, struct search_node *node, struct value *arg,
   retval->v.number = t <= mesg_time && mesg_time <= t + 86400;
-}                   
+}
 
@@ -1032,3 +1208,3 @@ cond_sentsince (struct parsebuf *pb, struct search_node *node,
   retval->v.number = mesg_time >= t;
-}                
+}
 
@@ -1042,3 +1218,3 @@ cond_since (struct parsebuf *pb, struct search_node *node, struct value *arg,
   mu_envelope_t env;
-  
+
   mu_message_get_envelope (pb->msg, &env);
@@ -1052,3 +1228,3 @@ cond_since (struct parsebuf *pb, struct search_node *node, struct value *arg,
     }
-}                    
+}
 
@@ -1059,3 +1235,3 @@ cond_smaller (struct parsebuf *pb, struct search_node *node, struct value *arg,
   size_t size = 0;
-  
+
   mu_message_size (pb->msg, &size);
@@ -1063,3 +1239,3 @@ cond_smaller (struct parsebuf *pb, struct search_node *node, struct value *arg,
   retval->v.number = size < arg[0].v.number;
-}                  
+}
 
@@ -1071,3 +1247,3 @@ cond_subject (struct parsebuf *pb, struct search_node *node, struct value *arg,
   retval->v.number = _scan_header (pb, MU_HEADER_SUBJECT, arg[0].v.string);
-}                  
+}
 
@@ -1080,3 +1256,3 @@ cond_text (struct parsebuf *pb, struct search_node *node, struct value *arg,
   retval->v.number = _scan_header_all (pb, s) || _scan_body (pb, s);
-}                     
+}
 
@@ -1088,3 +1264,3 @@ cond_to (struct parsebuf *pb, struct search_node *node, struct value *arg,
   retval->v.number = _scan_header (pb, MU_HEADER_TO, arg[0].v.string);
-}                       
+}
 
@@ -1096,3 +1272,3 @@ cond_uid (struct parsebuf *pb, struct search_node *node, struct value *arg,
   size_t uid = 0;
-  
+
   mu_message_get_uid (pb->msg, &uid);
@@ -1101,3 +1277,27 @@ cond_uid (struct parsebuf *pb, struct search_node *node, struct value *arg,
   retval->v.number = rc == 0;
-}                      
+}
 
+/* Return 1 if the CHARSET is available.
+   This function assumes that charset is available if it is possible
+   to create a filter for encoding ASCII data into it.
+ */
+static int
+available_charset (const char *charset)
+{
+  int rc;
+  mu_stream_t flt;
+  mu_stream_t null;
+  char const *argv[] = { "iconv", "US-ASCII", NULL, NULL };
+
+  rc = mu_nullstream_create (&null, MU_STREAM_READ);
+  if (rc)
+    return 0;
+  argv[2] = charset;
+  rc = mu_filter_chain_create (&flt, null, MU_FILTER_ENCODE, MU_STREAM_READ,
+			       MU_ARRAY_SIZE (argv) - 1, (char**) argv);
+  mu_stream_unref (null);
+  if (rc)
+    return 0;
+  mu_stream_destroy (&flt);
+  return 1;
+}
diff --git a/imap4d/util.c b/imap4d/util.c
index 19a7d82fd..cc494788b 100644
--- a/imap4d/util.c
+++ b/imap4d/util.c
@@ -158,10 +158,2 @@ util_parse_ctime_date (const char *date, time_t *timep,
 
-/* Return the first ocurrence of NEEDLE in HAYSTACK. Case insensitive
-   comparison */
-char *
-util_strcasestr (const char *haystack, const char *needle)
-{
-  return mu_c_strcasestr (haystack, needle);
-}
-
 void
diff --git a/libmailutils/mailbox/header.c b/libmailutils/mailbox/header.c
index 66af14209..98433b740 100644
--- a/libmailutils/mailbox/header.c
+++ b/libmailutils/mailbox/header.c
@@ -690,4 +690,4 @@ int
 mu_header_aget_value_n (mu_header_t header,
-		      const char *name, int n,
-		      char **pval)
+			const char *name, int n,
+			char **pval)
 {