strutil: support special case in power of two calculation

The sr_next_power_of_two() helper routine rejected input value 0
(an index), considered this case invalid. It is not, requires 1 bit
to hold the value. Return a "power of two" value of 1 for that input,
callers expect that result.

diff --git a/src/strutil.c b/src/strutil.c
index 841a682a2f4b89779043704c279e0c406eb244ab..2136bd4936c2fde5bf303bbf491e938af5d4acb1 100644 (file)
--- a/src/strutil.c
+++ b/src/strutil.c
@@ -1844,8 +1844,18 @@ SR_API int sr_next_power_of_two(size_t value, size_t *bits, size_t *power)
        if (power)
                *power = 0;
 
-       if (!value)
-               return SR_ERR_ARG;
+       /*
+        * Handle the special case of input value 0 (needs 1 bit
+        * and results in "power of two" value 1) here. It is not
+        * covered by the generic logic below.
+        */
+       if (!value) {
+               if (bits)
+                       *bits = 1;
+               if (power)
+                       *power = 1;
+               return SR_OK;
+       }
 
        need_bits = 0;
        check_mask = 0;