Fix potential memory error when joining filesystem paths

3 files changed, 12 insertions, 5 deletions

diff --git a/NEWS b/NEWS
index a9e4f2a..d93f736 100644
--- a/NEWS
+++ b/NEWS
@@ -1,3 +1,9 @@
+lilv (0.24.11) unstable;
+
+  * Fix potential memory error when joining filesystem paths
+
+ -- David Robillard <d@drobilla.net>  Wed, 11 Nov 2020 00:02:31 +0000
+
 lilv (0.24.10) stable;
 
   * Fix memory leaks in lv2bench
diff --git a/src/filesystem.c b/src/filesystem.c
index 7cda4d9..c8a58c1 100644
--- a/src/filesystem.c
+++ b/src/filesystem.c
@@ -199,10 +199,11 @@ lilv_path_join(const char* a, const char* b)
 		return (b && b[0]) ? lilv_strdup(b) : NULL;
 	}
 
-	const size_t a_len   = strlen(a);
-	const size_t b_len   = b ? strlen(b) : 0;
-	const size_t pre_len = a_len - (lilv_is_dir_sep(a[a_len - 1]) ? 1 : 0);
-	char*        path    = (char*)calloc(1, a_len + b_len + 2);
+	const size_t a_len        = strlen(a);
+	const size_t b_len        = b ? strlen(b) : 0;
+	const bool   a_end_is_sep = a_len > 0 && lilv_is_dir_sep(a[a_len - 1]);
+	const size_t pre_len      = a_len - (a_end_is_sep ? 1 : 0);
+	char*        path         = (char*)calloc(1, a_len + b_len + 2);
 	memcpy(path, a, pre_len);
 	path[pre_len] = '/';
 	if (b) {
diff --git a/wscript b/wscript
index f6780d0..2588fd4 100644
--- a/wscript
+++ b/wscript
@@ -12,7 +12,7 @@ from waflib.extras import autowaf
 # major increment <=> incompatible changes
 # minor increment <=> compatible changes (additions)
 # micro increment <=> no interface changes
-LILV_VERSION       = '0.24.10'
+LILV_VERSION       = '0.24.11'
 LILV_MAJOR_VERSION = '0'
 
 # Mandatory waf variables