Re: [Patch v8 01/18] parse_tag_line: use enum for return value.

Subject: Re: [Patch v8 01/18] parse_tag_line: use enum for return value.

Date: Fri, 21 Dec 2012 09:29:57 -0400

To: notmuch@notmuchmail.org

Cc:

From: David Bremner


david@tethera.net writes:

> From: David Bremner <bremner@debian.org>
>
> This is essentially cosmetic, since success=0 is promised by
> the comments in tag-utils.h.

In an amazing display of skill and style, in attempting to abort a git
send-email run so that I could rebase that last fixup away, I managed to
send the series without the cover letter. So, no point sending the whole
thing again just for that.

This ever-growing series obsoletes 

     id:1355492062-7546-1-git-send-email-david@tethera.net

I think I decided to ignore 

      id:871uettxln.fsf@qmul.ac.uk

Perhaps that should be documented, I'm not sure. Since the batch tagging
interface also allows you to remove strangely named tags, I think it is
ok.

Hopefully the new man page clears up what is and isn't allowed for
unencoded characters. Since spaces are the only thing used as
(top-level) delimiters now, they are the only thing "compressed" by
strtok_len.

For id:87vcc2q5n2.fsf@nikula.org, there is a seperate series
id:1355716788-2940-1-git-send-email-david@tethera.net to fix the memory
leak/allocation confusion. This series needs to be rebased onto the
final version of that one. I decided _not_ to relax the requirement that
the ':' marking a prefix be un-encoded, but rather update the
documentation.

A summary of changes to the series follows; I left out the interdiff for
the notmuch-tag man page, and things that got their own new commit.

----------------------------------------------------------------------
commit 30adcab7678296b22d86da06d472c3920c336747
Author: David Bremner <bremner@debian.org>
Date:   Sat Dec 15 15:17:40 2012 -0400

    fixup: clarify TAG_FLAG_ID_ONLY comments and name

diff --git a/notmuch-restore.c b/notmuch-restore.c
index 112f2f3..1b66e76 100644
--- a/notmuch-restore.c
+++ b/notmuch-restore.c
@@ -208,7 +208,7 @@ notmuch_restore_command (unused (void *ctx), int argc, char *argv[])
 	if (input_format == DUMP_FORMAT_SUP) {
 	    ret = parse_sup_line (ctx, line, &query_string, tag_ops);
 	} else {
-	    ret = parse_tag_line (ctx, line, TAG_FLAG_BE_GENEROUS | TAG_FLAG_ID_ONLY,
+	    ret = parse_tag_line (ctx, line, TAG_FLAG_BE_GENEROUS | TAG_FLAG_ID_DIRECT,
 				  &query_string, tag_ops);
 	}
 
diff --git a/tag-util.c b/tag-util.c
index 8fea76c..37bffd5 100644
--- a/tag-util.c
+++ b/tag-util.c
@@ -201,7 +201,7 @@ parse_tag_line (void *ctx, char *line,
     }
 
     /* tok now points to the query string */
-    if (flags & TAG_FLAG_ID_ONLY) {
+    if (flags & TAG_FLAG_ID_DIRECT) {
 	/* this is under the assumption that any whitespace in the
 	 * message-id must be hex-encoded. The check is probably not
 	 * perfect for exotic unicode whitespace; as fallback the
diff --git a/tag-util.h b/tag-util.h
index 7674051..eec00cf 100644
--- a/tag-util.h
+++ b/tag-util.h
@@ -28,8 +28,10 @@ typedef enum {
      */
     TAG_FLAG_BE_GENEROUS = (1 << 3),
 
-    /* Query consists of a single id:$message-id */
-    TAG_FLAG_ID_ONLY = (1 << 4)
+    /* Directly look up messages by hex-decoded message-id, rather
+     * than parsing a general query. The query MUST be of the form
+     * id:$message-id. */
+    TAG_FLAG_ID_DIRECT = (1 << 4)
 
 } tag_op_flag_t;
 

commit 256ec05a347b949e6b2bda0d2b6902ed8ab3fab3
Author: David Bremner <bremner@debian.org>
Date:   Sat Dec 15 19:54:05 2012 -0400

    fixup for id:87sj778ajb.fsf@qmul.ac.uk and id:87zk1fot39.fsf@nikula.org

diff --git a/notmuch-tag.c b/notmuch-tag.c
index 44b5bb4..5c8bad4 100644
--- a/notmuch-tag.c
+++ b/notmuch-tag.c
@@ -65,14 +65,16 @@ _optimize_tag_query (void *ctx, const char *orig_query_string,
     else
 	query_string = talloc_asprintf (ctx, "( %s ) and (", orig_query_string);
 
-
     /* Boolean terms surrounded by double quotes can contain any
      * character.  Double quotes are quoted by doubling them. */
 
     for (i = 0; i < tag_op_list_size (list) && query_string; i++) {
-	double_quote_str (ctx,
-			  tag_op_list_tag (list, i),
-			  &escaped, &escaped_len);
+	/* XXX in case of OOM, query_string will be deallocated when
+	 * ctx is, which might be at shutdown */
+	if (double_quote_str (ctx,
+			      tag_op_list_tag (list, i),
+			      &escaped, &escaped_len))
+	    return NULL;
 
 	query_string = talloc_asprintf_append_buffer (
 	    query_string, "%s%stag:%s", join,
diff --git a/util/string-util.c b/util/string-util.c
index ea7c25b..b9039f4 100644
--- a/util/string-util.c
+++ b/util/string-util.c
@@ -46,8 +46,11 @@ double_quote_str (void *ctx, const char *str,
     for (in = str; *in; in++)
 	needed += (*in == '"') ? 2 : 1;
 
-    if (needed > *len)
-	*buf = talloc_realloc (ctx, *buf, char, 2*needed);
+    if ((*buf == NULL) || (needed > *len)) {
+	*len = 2 * needed;
+	*buf = talloc_realloc (ctx, *buf, char, *len);
+    }
+
 
     if (! *buf)
 	return 1;
@@ -62,7 +65,7 @@ double_quote_str (void *ctx, const char *str,
 	*out++ = *in++;
     }
     *out++ = '"';
-    *out = 0;
+    *out = '\0';
 
     return 0;
 }
diff --git a/util/string-util.h b/util/string-util.h
index b593bc7..4fc7942 100644
--- a/util/string-util.h
+++ b/util/string-util.h
@@ -23,7 +23,7 @@ char *strtok_len (char *s, const char *delim, size_t *len);
  * Any internal double-quotes are doubled, i.e. a"b -> "a""b"
  *
  * Output is into buf; it may be talloc_realloced
- * return 0 on success, non-zero on failure.
+ * Return: 0 on success, non-zero on memory allocation failure.
  */
 int double_quote_str (void *talloc_ctx, const char *str,
 		      char **buf, size_t *len);

commit 4b26ac6f99c74cced64cfae317e6ac4b6a8f706f
Author: David Bremner <bremner@debian.org>
Date:   Mon Dec 17 23:36:30 2012 -0400

    fixup: rewrite decode+quote function for queries.
    
    Rather than splitting on ':' at the top level, we examine each space
    delimited token for a prefix.

diff --git a/tag-util.c b/tag-util.c
index 37bffd5..b0a846b 100644
--- a/tag-util.c
+++ b/tag-util.c
@@ -56,9 +56,14 @@ illegal_tag (const char *tag, notmuch_bool_t remove)
     return NULL;
 }
 
+/* Input is a hex encoded string, presumed to be a query for Xapian.
+ *
+ * Space delimited tokens are decoded and quoted, with '*' and prefixes
+ * of the form "foo:" passed through unquoted.
+ */
 static tag_parse_status_t
-quote_and_decode_query (void *ctx, char *encoded, const char *line_for_error,
-			char **query_string)
+unhex_and_quote (void *ctx, char *encoded, const char *line_for_error,
+		 char **query_string)
 {
     char *tok = encoded;
     size_t tok_len = 0;
@@ -68,14 +73,43 @@ quote_and_decode_query (void *ctx, char *encoded, const char *line_for_error,
 
     *query_string = talloc_strdup (ctx, "");
 
-    while (*query_string &&
-	   (tok = strtok_len (tok + tok_len, ": ", &tok_len)) != NULL) {
-	char delim = tok[tok_len];
+    while ((tok = strtok_len (tok + tok_len, " ", &tok_len)) != NULL) {
+
+	size_t prefix_len;
+	char delim = *(tok + tok_len);
 
 	*(tok + tok_len++) = '\0';
 
-	if (strcspn (tok, "%") < tok_len - 1) {
-	    /* something to decode */
+	prefix_len = hex_invariant (tok, tok_len);
+
+	if ((strcmp (tok, "*") == 0) || prefix_len >= tok_len - 1) {
+
+	    /* pass some things through without quoting or decoding.
+	     * Note for '*' this is mandatory.
+	     */
+
+	    if (! (*query_string = talloc_asprintf_append_buffer (
+		       *query_string, "%s%c", tok, delim))) {
+
+		ret = line_error (TAG_PARSE_OUT_OF_MEMORY,
+				  line_for_error, "aborting");
+		goto DONE;
+	    }
+
+	} else {
+	    /* potential prefix: one for ':', then something after */
+	    if ((tok_len - prefix_len > 2) && *(tok + prefix_len) == ':') {
+		if (! (*query_string = talloc_strndup_append (*query_string,
+							      tok,
+							      prefix_len + 1))) {
+		    ret = line_error (TAG_PARSE_OUT_OF_MEMORY,
+				      line_for_error, "aborting");
+		    goto DONE;
+		}
+		tok += prefix_len + 1;
+		tok_len -= prefix_len + 1;
+	    }
+
 	    if (hex_decode_inplace (tok) != HEX_SUCCESS) {
 		ret = line_error (TAG_PARSE_INVALID, line_for_error,
 				  "hex decoding of token '%s' failed", tok);
@@ -87,17 +121,14 @@ quote_and_decode_query (void *ctx, char *encoded, const char *line_for_error,
 				  line_for_error, "aborting");
 		goto DONE;
 	    }
-	    *query_string = talloc_asprintf_append_buffer (
-		*query_string, "%s%c", buf, delim);
 
-	} else {
-	    /* This is not just an optimization, but used to preserve
-	     * prefixes like id:, which cannot be quoted.
-	     */
-	    *query_string = talloc_asprintf_append_buffer (
-		*query_string, "%s%c", tok, delim);
+	    if (! (*query_string = talloc_asprintf_append_buffer (
+		       *query_string, "%s%c", buf, delim))) {
+		ret = line_error (TAG_PARSE_OUT_OF_MEMORY,
+				  line_for_error, "aborting");
+		goto DONE;
+	    }
 	}
-
     }
 
   DONE:
@@ -220,7 +251,7 @@ parse_tag_line (void *ctx, char *line,
 	/* skip 'id:' */
 	*query_string = tok + 3;
     } else {
-	ret = quote_and_decode_query (ctx, tok, line_for_error, query_string);
+	ret = unhex_and_quote (ctx, tok, line_for_error, query_string);
     }
 
   DONE:




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