Fix several issues with xdelta

1) The changes to sync.c look big but there are mostly caused by
the indentation. Fix a bug where download_size == 0 because the packages and
deltas are already in the cache, but we still need to build the deltas list
and apply the deltas to create the final package.

2) Fix the gzip / md5sum issue by switching to xdelta3, disabling external
recompression and using gzip -n in pacman, and disable bsdtar compression
and using gzip -n in makepkg.

Signed-off-by: Xavier Chantry <shiningxc@gmail.com>

2 files changed, 66 insertions, 57 deletions

diff --git a/lib/libalpm/delta.c b/lib/libalpm/delta.c
index 9e4bcb42..de5dd601 100644
--- a/lib/libalpm/delta.c
+++ b/lib/libalpm/delta.c
@@ -21,6 +21,7 @@
 
 #include <stdlib.h>
 #include <string.h>
+#include <stdint.h> /* intmax_t */
 #include <limits.h>
 #include <sys/types.h>
 #include <regex.h>
@@ -215,13 +216,13 @@ off_t _alpm_shortest_delta_path(alpm_list_t *deltas,
 		return(bestsize);
 	}
 
-	_alpm_log(PM_LOG_DEBUG, "started delta shortest-path search\n");
+	_alpm_log(PM_LOG_DEBUG, "started delta shortest-path search for '%s'\n", to);
 
 	vertices = delta_graph_init(deltas);
 
 	bestsize = delta_vert(vertices, to, &bestpath);
 
-	_alpm_log(PM_LOG_DEBUG, "delta shortest-path search complete\n");
+	_alpm_log(PM_LOG_DEBUG, "delta shortest-path search complete : '%jd'\n", (intmax_t)bestsize);
 
 	alpm_list_free_inner(vertices, _alpm_graph_free);
 	alpm_list_free(vertices);
diff --git a/lib/libalpm/sync.c b/lib/libalpm/sync.c
index fca96d8f..49ea3c27 100644
--- a/lib/libalpm/sync.c
+++ b/lib/libalpm/sync.c
@@ -27,6 +27,7 @@
 #include <stdio.h>
 #include <fcntl.h>
 #include <string.h>
+#include <stdint.h> /* intmax_t */
 #include <unistd.h>
 #include <time.h>
 #include <dirent.h>
@@ -387,8 +388,8 @@ static int compute_download_size(pmpkg_t *newpkg)
 		size = alpm_pkg_get_size(newpkg);
 	}
 
-	_alpm_log(PM_LOG_DEBUG, "setting download size %lld for pkg %s\n",
-			(long long)size, alpm_pkg_get_name(newpkg));
+	_alpm_log(PM_LOG_DEBUG, "setting download size %jd for pkg %s\n",
+			(intmax_t)size, alpm_pkg_get_name(newpkg));
 
 	newpkg->download_size = size;
 	return(0);
@@ -679,6 +680,12 @@ off_t SYMEXPORT alpm_pkg_download_size(pmpkg_t *newpkg)
 	return(newpkg->download_size);
 }
 
+static int endswith(char *filename, char *extension)
+{
+	char *s = filename + strlen(filename) - strlen(extension);
+	return (strcmp(s, extension) == 0);
+}
+
 /** Applies delta files to create an upgraded package file.
  *
  * All intermediate files are deleted, leaving only the starting and
@@ -724,16 +731,18 @@ static int apply_deltas(pmtrans_t *trans)
 			CALLOC(to, len, sizeof(char), RET_ERR(PM_ERR_MEMORY, 1));
 			snprintf(to, len, "%s/%s", cachedir, d->to);
 
-			/* an example of the patch command: (using /cache for cachedir)
-			 * xdelta patch /path/to/pacman_3.0.0-1_to_3.0.1-1-i686.delta \
-			 *              /path/to/pacman-3.0.0-1-i686.pkg.tar.gz       \
-			 *              /cache/pacman-3.0.1-1-i686.pkg.tar.gz
-			 */
-
 			/* build the patch command */
-			snprintf(command, PATH_MAX, "xdelta patch %s %s %s", delta, from, to);
+			/* compression command */
+			char *compress = "cat";
+			if(endswith(to, ".gz")) {
+				compress = "gzip -n";
+			} else if(endswith(to, ".bz2")) {
+				compress = "bzip";
+			}
+			/* -R for disabling external recompression, -c for sending to stdout */
+			snprintf(command, PATH_MAX, "xdelta3 -d -q -R -c -s %s %s | %s > %s", from, delta, compress, to);
 
-			_alpm_log(PM_LOG_DEBUG, _("command: %s\n"), command);
+			_alpm_log(PM_LOG_DEBUG, "command: %s\n", command);
 
 			EVENT(trans, PM_TRANS_EVT_DELTA_PATCH_START, d->to, d->delta);
 
@@ -847,29 +856,31 @@ int _alpm_sync_commit(pmtrans_t *trans, pmdb_t *db_local, alpm_list_t **data)
 
 				fname = alpm_pkg_get_filename(spkg);
 				ASSERT(fname != NULL, RET_ERR(PM_ERR_PKG_INVALID_NAME, -1));
-				if(spkg->download_size != 0) {
-					alpm_list_t *delta_path = spkg->delta_path;
-					if(delta_path) {
-						alpm_list_t *dlts = NULL;
-
-						for(dlts = delta_path; dlts; dlts = dlts->next) {
-							pmdelta_t *d = dlts->data;
-
-							if(d->download_size != 0) {
-								/* add the delta filename to the download list if
-								 * it's not in the cache */
-								files = alpm_list_add(files, strdup(d->delta));
-							}
-
-							/* keep a list of the delta files for md5sums */
-							deltas = alpm_list_add(deltas, d);
+				alpm_list_t *delta_path = spkg->delta_path;
+				if(delta_path) {
+					/* using deltas */
+					alpm_list_t *dlts = NULL;
+
+					for(dlts = delta_path; dlts; dlts = dlts->next) {
+						pmdelta_t *d = dlts->data;
+
+						if(d->download_size != 0) {
+							/* add the delta filename to the download list if needed */
+							files = alpm_list_add(files, strdup(d->delta));
 						}
 
-					} else {
-						/* not using deltas, so add the file to the download list */
+						/* keep a list of all the delta files for md5sums */
+						deltas = alpm_list_add(deltas, d);
+					}
+
+				} else {
+					/* not using deltas */
+					if(spkg->download_size != 0) {
+						/* add the filename to the download list if needed */
 						files = alpm_list_add(files, strdup(fname));
 					}
 				}
+
 			}
 		}
 
@@ -890,37 +901,34 @@ int _alpm_sync_commit(pmtrans_t *trans, pmdb_t *db_local, alpm_list_t **data)
 		handle->totaldlcb(0);
 	}
 
-	if(handle->usedelta) {
+	/* if we have deltas to work with */
+	if(handle->usedelta && deltas) {
 		int ret = 0;
-
-		/* only output if there are deltas to work with */
-		if(deltas) {
-			errors = 0;
-			/* Check integrity of deltas */
-			EVENT(trans, PM_TRANS_EVT_DELTA_INTEGRITY_START, NULL, NULL);
-
-			for(i = deltas; i; i = i->next) {
-				pmdelta_t *d = alpm_list_getdata(i);
-				const char *filename = alpm_delta_get_filename(d);
-				const char *md5sum = alpm_delta_get_md5sum(d);
-
-				if(test_md5sum(trans, filename, md5sum) != 0) {
-					errors++;
-					*data = alpm_list_add(*data, strdup(filename));
-				}
+		errors = 0;
+		/* Check integrity of deltas */
+		EVENT(trans, PM_TRANS_EVT_DELTA_INTEGRITY_START, NULL, NULL);
+
+		for(i = deltas; i; i = i->next) {
+			pmdelta_t *d = alpm_list_getdata(i);
+			const char *filename = alpm_delta_get_filename(d);
+			const char *md5sum = alpm_delta_get_md5sum(d);
+
+			if(test_md5sum(trans, filename, md5sum) != 0) {
+				errors++;
+				*data = alpm_list_add(*data, strdup(filename));
 			}
-			if(errors) {
-				pm_errno = PM_ERR_DLT_INVALID;
-				goto error;
-			}
-			EVENT(trans, PM_TRANS_EVT_DELTA_INTEGRITY_DONE, NULL, NULL);
+		}
+		if(errors) {
+			pm_errno = PM_ERR_DLT_INVALID;
+			goto error;
+		}
+		EVENT(trans, PM_TRANS_EVT_DELTA_INTEGRITY_DONE, NULL, NULL);
 
-			/* Use the deltas to generate the packages */
-			EVENT(trans, PM_TRANS_EVT_DELTA_PATCHES_START, NULL, NULL);
-			ret = apply_deltas(trans);
-			EVENT(trans, PM_TRANS_EVT_DELTA_PATCHES_DONE, NULL, NULL);
+		/* Use the deltas to generate the packages */
+		EVENT(trans, PM_TRANS_EVT_DELTA_PATCHES_START, NULL, NULL);
+		ret = apply_deltas(trans);
+		EVENT(trans, PM_TRANS_EVT_DELTA_PATCHES_DONE, NULL, NULL);
 
-		}
 		if(ret) {
 			pm_errno = PM_ERR_DLT_PATCHFAILED;
 			goto error;