workspace_next_name: fix string length for ws_num >= 100

The check didn't include && ws_num < 100 so l would always be 1 or 2
Instead of fixing logic it's simpler to just call snprintf twice to get
length and use that.

Also change malloc failure check to sway_assert because both callers of
this function do not do null check and would segfault...

Found through static analysis.

1 files changed, 2 insertions, 8 deletions

diff --git a/sway/tree/workspace.c b/sway/tree/workspace.c
index 3a311cd1..2db06a31 100644
--- a/sway/tree/workspace.c
+++ b/sway/tree/workspace.c
@@ -109,7 +109,6 @@ static bool workspace_valid_on_output(const char *output_name,
 char *workspace_next_name(const char *output_name) {
         wlr_log(L_DEBUG, "Workspace: Generating new workspace name for output %s",
                         output_name);
-        int l = 1;
         // Scan all workspace bindings to find the next available workspace name,
         // if none are found/available then default to a number
         struct sway_mode *mode = config->current_mode;
@@ -202,14 +201,9 @@ char *workspace_next_name(const char *output_name) {
         // As a fall back, get the current number of active workspaces
         // and return that + 1 for the next workspace's name
         int ws_num = root_container.children->length;
-        if (ws_num >= 10) {
-                l = 2;
-        } else if (ws_num >= 100) {
-                l = 3;
-        }
+        int l = snprintf(NULL, 0, "%d", ws_num);
         char *name = malloc(l + 1);
-        if (!name) {
-                wlr_log(L_ERROR, "Could not allocate workspace name");
+        if (!sway_assert(name, "Cloud not allocate workspace name")) {
                 return NULL;
         }
         sprintf(name, "%d", ws_num++);