From: Andres Mejia <amejia004@gmail.com>
Date: Sat, 26 Jan 2013 03:01:56 +0000 (-0500)
Subject: Give formats/filters way to know data amount requested from archive_read_data().
X-Git-Tag: v3.1.2~55
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=a16da62ba7771eebd3807e18513195d0f0607d8d;p=thirdparty%2Flibarchive.git

Give formats/filters way to know data amount requested from archive_read_data().
---

diff --git a/libarchive/archive_read.c b/libarchive/archive_read.c
index c569a63fe..048c316c5 100644
--- a/libarchive/archive_read.c
+++ b/libarchive/archive_read.c
@@ -660,6 +660,8 @@ _archive_read_next_header2(struct archive *_a, struct archive_entry *entry)
 
 	a->read_data_output_offset = 0;
 	a->read_data_remaining = 0;
+	a->read_data_is_posix_read = 0;
+	a->read_data_requested = 0;
 	a->data_start_node = a->client.cursor;
 	/* EOF always wins; otherwise return the worst error. */
 	return (r2 < r1 || r2 == ARCHIVE_EOF) ? r2 : r1;
@@ -771,6 +773,8 @@ archive_read_data(struct archive *_a, void *buff, size_t s)
 	while (s > 0) {
 		if (a->read_data_remaining == 0) {
 			read_buf = a->read_data_block;
+			a->read_data_is_posix_read = 1;
+			a->read_data_requested = s;
 			r = _archive_read_data_block(&a->archive, &read_buf,
 			    &a->read_data_remaining, &a->read_data_offset);
 			a->read_data_block = read_buf;
@@ -824,6 +828,8 @@ archive_read_data(struct archive *_a, void *buff, size_t s)
 			bytes_read += len;
 		}
 	}
+	a->read_data_is_posix_read = 0;
+	a->read_data_requested = 0;
 	return (bytes_read);
 }
 
diff --git a/libarchive/archive_read_private.h b/libarchive/archive_read_private.h
index 587c8a33e..8a6c859a8 100644
--- a/libarchive/archive_read_private.h
+++ b/libarchive/archive_read_private.h
@@ -161,6 +161,14 @@ struct archive_read {
 	int64_t		  read_data_output_offset;
 	size_t		  read_data_remaining;
 
+	/*
+	 * Used by formats/filters to determine the amount of data
+	 * requested from a call to archive_read_data(). This is only
+	 * useful when the format/filter has seek support.
+	 */
+	char		  read_data_is_posix_read;
+	size_t		  read_data_requested;
+
 	/* Callbacks to open/read/write/close client archive streams. */
 	struct archive_read_client client;
 
diff --git a/libarchive/archive_read_support_format_rar.c b/libarchive/archive_read_support_format_rar.c
index 1bd95a395..632908ea1 100644
--- a/libarchive/archive_read_support_format_rar.c
+++ b/libarchive/archive_read_support_format_rar.c
@@ -2796,6 +2796,8 @@ rar_read_ahead(struct archive_read *a, size_t min, ssize_t *avail)
   int ret;
   if (avail)
   {
+    if (a->read_data_is_posix_read && *avail > (ssize_t)a->read_data_requested)
+      *avail = a->read_data_requested;
     if (*avail > rar->bytes_remaining)
       *avail = (ssize_t)rar->bytes_remaining;
     if (*avail < 0)