scan-build: fix a couple of minor warnings from a scan-build run

csi.c

@@ -54,8 +54,8 @@ csi_as_string(struct terminal *term, uint8_t final)
                       i == term->vt.params.idx - 1 ? "" : ";");
     }
 
-    c += snprintf(&msg[c], sizeof(msg) - c, "%c (%zu parameters)",
-                  final, term->vt.params.idx);
+    snprintf(&msg[c], sizeof(msg) - c, "%c (%zu parameters)",
+             final, term->vt.params.idx);
     return msg;
 }
 

log.c

@@ -100,7 +100,7 @@ _sys_log(enum log_class log_class, const char *module,
     idx += vsnprintf(&msg[idx], required_len + 1 - idx, fmt, va);
 
     if (sys_errno != 0) {
-        idx += snprintf(
+        snprintf(
             &msg[idx], required_len + 1 - idx, ": %s", strerror(sys_errno));
     }
 

main.c

@@ -143,6 +143,7 @@ main(int argc, char *const *argv)
             unsigned width, height;
             if (sscanf(optarg, "%ux%u", &width, &height) != 2 || width == 0 || height == 0) {
                 fprintf(stderr, "error: invalid geometry: %s\n", optarg);
+                config_free(conf);
                 return EXIT_FAILURE;
             }
 

selection.c

@@ -108,6 +108,7 @@ extract_selection(const struct terminal *term)
         start_col = 0;
     }
 
+    assert(idx > 0);
     assert(idx < buf_size);
     if (buf[idx - 1] == '\n')
         buf[idx - 1] = '\0';

shm.c

@@ -148,7 +148,7 @@ shm_get_buffer(struct wl_shm *shm, int width, int height, unsigned long cookie)
 
     /* We use the entire pool for our single buffer */
     wl_shm_pool_destroy(pool); pool = NULL;
-    close(pool_fd); pool_fd = -1;
+    close(pool_fd);
 
     /* One pixman image for each worker thread (do we really need multiple?) */
     pix = pixman_image_create_bits_no_clear(

vt.c

@@ -581,7 +581,7 @@ esc_as_string(struct terminal *term, uint8_t final)
 
     assert(term->vt.params.idx == 0);
 
-    c += snprintf(&msg[c], sizeof(msg) - c, "%c", final);
+    snprintf(&msg[c], sizeof(msg) - c, "%c", final);
     return msg;
 
 }