[PATCH] build: avoid build failures on gcc <= 10, or clang

[Pádraig Brady]

On gcc 10 the following build failure occurs:
  "error: a label can only be part of a statement
   and a declaration is not a statement"
This is because the current code is non standards conforming,
but GCC >= 11 will compile it (even with the -Wpedantic option).
This issue is tracked for GCC at:
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=111526

* src/tail.c (parse_options): Avoid a declaration after label,
by using a surrounding block.
---
 src/tail.c | 12 +++++++-----
 1 file changed, 7 insertions(+), 5 deletions(-)

diff --git a/src/tail.c b/src/tail.c
index 904a76d01..4c3c7b590 100644
--- a/src/tail.c
+++ b/src/tail.c
@@ -2208,11 +2208,13 @@ parse_options (int argc, char **argv,
           break;
 
         case PID_OPTION:
-          pid_t pid =
-            xdectoumax (optarg, 0, PID_T_MAX, "", _("invalid PID"), 0);
-          pids = xreallocarray (pids, nbpids + 1, sizeof (pid_t));
-          pids[nbpids] = pid;
-          nbpids++;
+          {
+            pid_t pid =
+              xdectoumax (optarg, 0, PID_T_MAX, "", _("invalid PID"), 0);
+            pids = xreallocarray (pids, nbpids + 1, sizeof (pid_t));
+            pids[nbpids] = pid;
+            nbpids++;
+          }
           break;
 
         case PRESUME_INPUT_PIPE_OPTION:
-- 
2.41.0