support: Use CHAR_MAX as maximum value

On ABIs with defined 'char' was unsigned type, clang fails to build
support_process_state.c with:

  support_process_state.c:70:21: error: result of comparison of constant  -1 with expression of type 'char' is always false [-Werror,-Wtautological-constant-out-of-range-compare]
     70 |       if (cur_state == -1)
        |           ~~~~~~~~~ ^  ~~
  1 error generated.

Reviewed-by: Sam James <sam@gentoo.org>

diff --git a/support/support_process_state.c b/support/support_process_state.c
index d2cb5461364c904e10c45c643d58bf22631edb42..8f8e118ce9e1a9431e9e5969934b93152fbee5f6 100644 (file)
--- a/support/support_process_state.c
+++ b/support/support_process_state.c
@@ -59,7 +59,7 @@ support_process_state_wait (pid_t pid, enum support_process_state state)
 
   for (;;)
     {
-      char cur_state = -1;
+      char cur_state = CHAR_MAX;
       while (xgetline (&line, &linesiz, fstatus) > 0)
        if (strncmp (line, "State:", strlen ("State:")) == 0)
          {
@@ -67,7 +67,7 @@ support_process_state_wait (pid_t pid, enum support_process_state state)
            break;
          }
       /* Fallback to nanosleep for invalid state.  */
-      if (cur_state == -1)
+      if (cur_state == CHAR_MAX)
        break;
 
       for (size_t i = 0; i < array_length (process_states); ++i)