[lttng-dev] [lttng-tools PATCH 3/5] Fix: utils_expand_path now works for paths that ends with '/.' or '/..'

[Raphaël Beamonte]

Cases where the path given ended with '/.' or '/..' were not handled
properly using the utils_expand_path function and the resulting path
was still showing this end part. This fix aims to treat that last
part and 'expand' it as expected.

Signed-off-by: Raphaël Beamonte <raphael.beamonte at gmail.com>
---
 src/common/utils.c |   27 +++++++++++++++++++++++++++
 1 file changed, 27 insertions(+)

diff --git a/src/common/utils.c b/src/common/utils.c
index 330c04e..ce25f23 100644
--- a/src/common/utils.c
+++ b/src/common/utils.c
@@ -178,6 +178,8 @@ LTTNG_HIDDEN
 char *utils_expand_path(const char *path)
 {
 	char *next, *previous, *slash, *start_path, *absolute_path = NULL;
+	char *last_token;
+	int is_dot, is_dotdot;
 
 	/* Safety net */
 	if (path == NULL) {
@@ -241,6 +243,31 @@ char *utils_expand_path(const char *path)
 				absolute_path, PATH_MAX);
 	}
 
+	/* Identify the last token */
+	last_token = strrchr(absolute_path, '/');
+
+	/* Verify that this token is not a relative path */
+	is_dotdot = (strcmp(last_token, "/..") == 0);
+	is_dot = (strcmp(last_token, "/.") == 0);
+
+	/* If it is, take action */
+	if (is_dot || is_dotdot) {
+		/* For both, remove this token */
+		*last_token = '\0';
+
+		/* If it was a reference to parent directory, go back one more time */
+		if (is_dotdot) {
+			last_token = strrchr(absolute_path, '/');
+
+			/* If there was only one level left, we keep the first '/' */
+			if (last_token == absolute_path) {
+				last_token++;
+			}
+
+			*last_token = '\0';
+		}
+	}
+
 	return absolute_path;
 
 error:
-- 
1.7.10.4