warning cleanup: unsigned < 0 comparisons.

This is the fourth round of an effort to enable GCC's -Wextra
option. Instances of code that test whether an unsigned
quantity is negative are repaired. Real bugs are found.

* itypes.c (c_u32, c_uint, c_ulong): Remove useless comparison
for < 0 that was copy-pasted from the signed cases.

* linenoise/linenoise.c (show_help, edit): Do not test the
return value of the getch_fn callback for negative. It returns
wint_t, which may be unsigned. Test for the WEOF value.
This is a bug because since the original comparison is
always false, the code fails to catch the WEOF return.

2 files changed, 7 insertions, 7 deletions

diff --git a/itypes.c b/itypes.c
index d5821638..ba8705e2 100644
--- a/itypes.c
+++ b/itypes.c
@@ -90,7 +90,7 @@ i32_t c_i32(val n, val self)
 u32_t c_u32(val n, val self)
 {
   uint_ptr_t v = c_unum(n);
-  if (v < 0 || v > 0xFFFFFFFF)
+  if (v > 0xFFFFFFFF)
     uw_throwf(error_s, lit("~a: value ~s is out of unsigned 32 bit range"),
               self, n, nao);
   return v;
@@ -228,7 +228,7 @@ int c_int(val n, val self)
 unsigned int c_uint(val n, val self)
 {
   uint_ptr_t v = c_unum(n);
-  if (v < 0 || v > UINT_MAX)
+  if (v > UINT_MAX)
     uw_throwf(error_s, lit("~a: value ~s is out of unsigned int range"),
               self, n, nao);
   return v;
@@ -253,7 +253,7 @@ unsigned long c_ulong(val n, val self)
 {
 #if SIZEOF_LONG <= SIZEOF_PTR
   uint_ptr_t v = c_unum(n);
-  if (v < 0 || v > ULONG_MAX)
+  if (v > ULONG_MAX)
     uw_throwf(error_s, lit("~a: value ~s is out of unsigned long range"),
               self, n, nao);
   return v;
diff --git a/linenoise/linenoise.c b/linenoise/linenoise.c
index 998314cf..83a08ec7 100644
--- a/linenoise/linenoise.c
+++ b/linenoise/linenoise.c
@@ -840,14 +840,14 @@ static void show_help(lino_t *l)
                 break;
             continue;
         case ESC:
-            if ((seq[0] = lino_os.getch_fn(l->tty_ifs)) < 0)
+            if ((seq[0] = lino_os.getch_fn(l->tty_ifs)) == WEOF)
                 break;
-            if ((seq[1] = lino_os.getch_fn(l->tty_ifs)) < 0)
+            if ((seq[1] = lino_os.getch_fn(l->tty_ifs)) == WEOF)
                 break;
 
             if (seq[0] == '[') {
                 if (seq[1] >= '0' && seq[1] <= '9') {
-                    if ((seq[2] = lino_os.getch_fn(l->tty_ifs)) < 0)
+                    if ((seq[2] = lino_os.getch_fn(l->tty_ifs)) == WEOF)
                         break;
                     if (seq[2] == '~') {
                         switch(seq[1]) {
@@ -2261,7 +2261,7 @@ static int edit(lino_t *l, const wchar_t *prompt)
             break;
         }
 
-        if (c < 0)
+        if (c == WEOF)
             goto out;
         if (c == 0)
             continue;