Use an external gzip program when zlib is unavailable.

1 files changed, 72 insertions, 10 deletions

diff --git a/libarchive/archive_write_add_filter_gzip.c b/libarchive/archive_write_add_filter_gzip.c
index 3d3f1f47..c7d3714f 100644
--- a/libarchive/archive_write_add_filter_gzip.c
+++ b/libarchive/archive_write_add_filter_gzip.c
@@ -43,6 +43,7 @@ __FBSDID("$FreeBSD: head/lib/libarchive/archive_write_set_compression_gzip.c 201
 
 #include "archive.h"
 #include "archive_private.h"
+#include "archive_string.h"
 #include "archive_write_private.h"
 
 #if ARCHIVE_VERSION_NUMBER < 4000000
@@ -54,24 +55,19 @@ archive_write_set_compression_gzip(struct archive *a)
 }
 #endif
 
-#ifndef HAVE_ZLIB_H
-int
-archive_write_add_filter_gzip(struct archive *a)
-{
-	archive_set_error(a, ARCHIVE_ERRNO_MISC,
-	    "gzip compression not supported on this platform");
-	return (ARCHIVE_FATAL);
-}
-#else
 /* Don't compile this if we don't have zlib. */
 
 struct private_data {
 	int		 compression_level;
+#ifdef HAVE_ZLIB_H
 	z_stream	 stream;
 	int64_t		 total_in;
 	unsigned char	*compressed;
 	size_t		 compressed_buffer_size;
 	unsigned long	 crc;
+#else
+	struct archive_write_program_data *pdata;
+#endif
 };
 
 /*
@@ -88,8 +84,10 @@ static int archive_compressor_gzip_write(struct archive_write_filter *,
 		    const void *, size_t);
 static int archive_compressor_gzip_close(struct archive_write_filter *);
 static int archive_compressor_gzip_free(struct archive_write_filter *);
+#ifdef HAVE_ZLIB_H
 static int drive_compressor(struct archive_write_filter *,
 		    struct private_data *, int finishing);
+#endif
 
 
 /*
@@ -110,21 +108,39 @@ archive_write_add_filter_gzip(struct archive *_a)
 		return (ARCHIVE_FATAL);
 	}
 	f->data = data;
-	data->compression_level = Z_DEFAULT_COMPRESSION;
 	f->open = &archive_compressor_gzip_open;
 	f->options = &archive_compressor_gzip_options;
 	f->close = &archive_compressor_gzip_close;
 	f->free = &archive_compressor_gzip_free;
 	f->code = ARCHIVE_FILTER_GZIP;
 	f->name = "gzip";
+#ifdef HAVE_ZLIB_H
+	data->compression_level = Z_DEFAULT_COMPRESSION;
 	return (ARCHIVE_OK);
+#else
+	data->pdata = __archive_write_program_allocate();
+	if (data->pdata == NULL) {
+		free(data);
+		archive_set_error(&a->archive, ENOMEM, "Out of memory");
+		return (ARCHIVE_FATAL);
+	}
+	data->compression_level = 0;
+	archive_set_error(&a->archive, ARCHIVE_ERRNO_MISC,
+	    "Using external gzip program");
+	return (ARCHIVE_WARN);
+#endif
 }
 
 static int
 archive_compressor_gzip_free(struct archive_write_filter *f)
 {
 	struct private_data *data = (struct private_data *)f->data;
+
+#ifdef HAVE_ZLIB_H
 	free(data->compressed);
+#else
+	__archive_write_program_free(data->pdata);
+#endif
 	free(data);
 	f->data = NULL;
 	return (ARCHIVE_OK);
@@ -153,6 +169,7 @@ archive_compressor_gzip_options(struct archive_write_filter *f, const char *key,
 	return (ARCHIVE_WARN);
 }
 
+#ifdef HAVE_ZLIB_H
 /*
  * Setup callback.
  */
@@ -367,4 +384,49 @@ drive_compressor(struct archive_write_filter *f,
 	}
 }
 
+#else /* HAVE_ZLIB_H */
+
+static int
+archive_compressor_gzip_open(struct archive_write_filter *f)
+{
+	struct private_data *data = (struct private_data *)f->data;
+	struct archive_string as;
+	int r;
+
+	archive_string_init(&as);
+	archive_strcpy(&as, "gzip");
+
+	/* Specify compression level. */
+	if (data->compression_level > 0) {
+		archive_strcat(&as, " -");
+		archive_strappend_char(&as, '0' + data->compression_level);
+	}
+	r = __archive_write_program_set_cmd(data->pdata, as.s);
+	archive_string_free(&as);
+	if (r != ARCHIVE_OK) {
+		archive_set_error(f->archive, ENOMEM, "Can't allocate memory");
+		return (ARCHIVE_FATAL);
+	}
+	f->write = archive_compressor_gzip_write;
+
+	return __archive_write_program_open(f, data->pdata);
+}
+
+static int
+archive_compressor_gzip_write(struct archive_write_filter *f, const void *buff,
+    size_t length)
+{
+	struct private_data *data = (struct private_data *)f->data;
+
+	return __archive_write_program_write(f, data->pdata, buff, length);
+}
+
+static int
+archive_compressor_gzip_close(struct archive_write_filter *f)
+{
+	struct private_data *data = (struct private_data *)f->data;
+
+	return __archive_write_program_close(f, data->pdata);
+}
+
 #endif /* HAVE_ZLIB_H */