common: cast arguments to character classification functions to unsigned char

[babeltrace.git] / src / common / common.c

diff --git a/src/common/common.c b/src/common/common.c
index 1a7d57cc2bb420520508336968ef155d6631b6bf..eed2451ea110400d151fde4ad0dddf558149bb56 100644 (file)
--- a/src/common/common.c
+++ b/src/common/common.c
@@ -783,7 +783,7 @@ bool bt_common_string_is_printable(const char *input)
        BT_ASSERT_DBG(input);
 
        for (ch = input; *ch != '\0'; ch++) {
-               if (!isprint(*ch) && *ch != '\n' && *ch != '\r' &&
+               if (!isprint((unsigned char) *ch) && *ch != '\n' && *ch != '\r' &&
                                *ch != '\t' && *ch != '\v') {
                        printable = false;
                        goto end;