[pacman-dev] [PATCH 2/3] pacsort, introduce define for escape_char error code

[Rikard Falkeborn]

The signedness of char is implementation defined. On systems where
char is unsigned, comparing a variable of type char with -1 is never
true, due to integer promotion rules. To avoid this, introduce a
define for invalid field separators where -1 is cast to char. This will
ensure that the return value check works for both unsigned and signed char.

Fixes one warning [-Wtype-limits] for comparissons with -1 when compiling
with -funsigned-char.

Signed-off-by: Rikard Falkeborn <rikard.falkeb...@gmail.com>
---
 src/util/pacsort.c | 11 ++++++-----
 1 file changed, 6 insertions(+), 5 deletions(-)

diff --git a/src/util/pacsort.c b/src/util/pacsort.c
index e7dc63e..dcf1ade 100644
--- a/src/util/pacsort.c
+++ b/src/util/pacsort.c
@@ -28,6 +28,7 @@
 #include "util-common.h"
 
 #define DELIM ' '
+#define INVALD_ESCAPE_CHAR ((char)-1)
 
 #ifndef MIN
 #define MIN(a, b)      \
@@ -385,13 +386,13 @@ static int vercmp(const void *p1, const void *p2)
 static char escape_char(const char *string)
 {
        if(!string) {
-               return -1;
+               return INVALD_ESCAPE_CHAR;
        }
 
        const size_t len = strlen(string);
 
        if(len > 2) {
-               return -1;
+               return INVALD_ESCAPE_CHAR;
        }
 
        if(len == 1) {
@@ -399,7 +400,7 @@ static char escape_char(const char *string)
        }
 
        if(*string != '\\') {
-               return -1;
+               return INVALD_ESCAPE_CHAR;
        }
 
        switch(string[1]) {
@@ -412,7 +413,7 @@ static char escape_char(const char *string)
                case '0':
                        return '\0';
                default:
-                       return -1;
+                       return INVALD_ESCAPE_CHAR;
        }
 }
 
@@ -463,7 +464,7 @@ static int parse_options(int argc, char **argv)
                                break;
                        case 't':
                                opts.delim = escape_char(optarg);
-                               if(opts.delim == -1) {
+                               if(opts.delim == INVALD_ESCAPE_CHAR) {
                                        fprintf(stderr, "error: invalid field 
separator -- `%s'\n", optarg);
                                        return 1;
                                }
-- 
2.6.4