gensquashfs: do pushd/popd when needed instead of chdir

This commit replaces the chdir to the input directory with pushd/popd
when building the fstree and again when packing files.

This simplifies handling of other file paths given on the command line
that have to be accessed and are relative to the original working
directories.

Signed-off-by: David Oberhollenzer <david.oberhollenzer@sigma-star.at>

1 files changed, 9 insertions, 14 deletions

diff --git a/lib/fstree/fstree_from_file.c b/lib/fstree/fstree_from_file.c
index 5a87222..affa769 100644
--- a/lib/fstree/fstree_from_file.c
+++ b/lib/fstree/fstree_from_file.c
@@ -365,6 +365,7 @@ out_desc:
 int fstree_from_file(fstree_t *fs, const char *filename, const char *rootdir)
 {
 	FILE *fp = fopen(filename, "rb");
+	bool need_restore = false;
 	size_t n, line_num = 0;
 	const char *ptr;
 	ssize_t ret;
@@ -379,26 +380,16 @@ int fstree_from_file(fstree_t *fs, const char *filename, const char *rootdir)
 		ptr = strrchr(filename, '/');
 
 		if (ptr != NULL) {
-			line = strndup(filename, ptr - filename);
-			if (line == NULL) {
-				perror("composing root path");
-				return -1;
-			}
-
-			if (chdir(line)) {
-				perror(line);
+			if (pushdn(filename, ptr - filename)) {
 				free(line);
 				return -1;
 			}
-
-			free(line);
-			line = NULL;
+			need_restore = true;
 		}
 	} else {
-		if (chdir(rootdir)) {
-			perror(rootdir);
+		if (pushd(rootdir))
 			return -1;
-		}
+		need_restore = true;
 	}
 
 	for (;;) {
@@ -433,6 +424,10 @@ int fstree_from_file(fstree_t *fs, const char *filename, const char *rootdir)
 	}
 
 	fclose(fp);
+
+	if (need_restore && popd() != 0)
+		return -1;
+
 	return 0;
 fail_line:
 	free(line);