Addressed copilot review comments

- Converted 'strncat' to the standard POSIX behavior. Fixed fdt-parser
  to use the right len argument.

Author: danielinux

src/string.c

@@ -117,11 +117,6 @@ int strcmp(const char *s1, const char *s2)
 }
 #endif /* Renesas CCRX */
 
-static int is_alpha(int c)
-{
-    return ((c >= 'A' && c <= 'Z') || (c >= 'a' && c <= 'z'));
-}
-
 int strcasecmp(const char *s1, const char *s2)
 {
     int diff = 0;
@@ -130,7 +125,7 @@ int strcasecmp(const char *s1, const char *s2)
         diff = (int)*s1 - (int)*s2;
 
         if (((diff == 'A' - 'a') || (diff == 'a' - 'A')) &&
-                (is_alpha((unsigned char)*s1) || is_alpha((unsigned char)*s2)))
+                (isalpha((unsigned char)*s1) && isalpha((unsigned char)*s2)))
             diff = 0;
 
         s1++;
@@ -149,7 +144,7 @@ int strncasecmp(const char *s1, const char *s2, size_t n)
         diff = (int)*s1 - (int)*s2;
 
         if (((diff == 'A' - 'a') || (diff == 'a' - 'A')) &&
-                (is_alpha((unsigned char)*s1) || is_alpha((unsigned char)*s2)))
+                (isalpha((unsigned char)*s1) && isalpha((unsigned char)*s2)))
             diff = 0;
 
         s1++;
@@ -163,16 +158,13 @@ int strncasecmp(const char *s1, const char *s2, size_t n)
 #if !defined(__CCRX__) /* Renesas CCRX */
 char *strncat(char *dest, const char *src, size_t n)
 {
-    size_t i = 0;
+    size_t i;
     size_t j = strlen(dest);
 
-    for (i = 0; i < strlen(src); i++) {
-        if (j >= (n - 1)) {
-            break;
-        }
-        dest[j++] = src[i];
+    for (i = 0; i < n && src[i] != '\0'; i++) {
+        dest[j + i] = src[i];
     }
-    dest[j] = '\0';
+    dest[j + i] = '\0';
 
     return dest;
 }

tools/fdt-parser/fdt-parser.c

@@ -498,7 +498,9 @@ int main(int argc, char *argv[])
         if (ret == 0) {
             char outfilename[PATH_MAX];
             strncpy(outfilename, filename, sizeof(outfilename)-1);
-            strncat(outfilename, ".out",   sizeof(outfilename)-1);
+            outfilename[sizeof(outfilename) - 1] = '\0';
+            strncat(outfilename, ".out",
+                sizeof(outfilename) - strlen(outfilename) - 1);
 
             /* save updated binary file */
             write_bin(outfilename, image, imageSz + UNIT_TEST_GROW_SIZE);

tools/unit-tests/unit-string.c

@@ -23,8 +23,6 @@
  */
 
 #define FAST_MEMCPY
-#define DEBUG_UART
-#define PRINTF_ENABLED
 
 #include <check.h>
 #include <stdint.h>
@@ -86,7 +84,9 @@ START_TEST(test_case_insensitive_alpha_only)
     ck_assert_int_ne(strcasecmp("@", "`"), 0);
     ck_assert_int_ne(strcasecmp("[", "{"), 0);
     ck_assert_int_ne(strcasecmp("]", "}"), 0);
+    ck_assert_int_ne(strcasecmp("!", "A"), 0);
     ck_assert_int_ne(strncasecmp("@", "`", 1), 0);
+    ck_assert_int_ne(strncasecmp("!", "A", 1), 0);
     ck_assert_int_ne(strcasecmp("a@", "A`"), 0);
     ck_assert_int_ne(strncasecmp("a@", "A`", 2), 0);
 }
@@ -171,11 +171,11 @@ START_TEST(test_strcpy_strncpy_strcat_strncat)
 
     strcpy(dest, "a");
     strncat(dest, "bc", 3);
-    ck_assert_str_eq(dest, "ab");
+    ck_assert_str_eq(dest, "abc");
 
     strcpy(dest, "a");
     strncat(dest, "bc", 1);
-    ck_assert_str_eq(dest, "a");
+    ck_assert_str_eq(dest, "ab");
 
     strcpy(dest, "");
     strncat(dest, "x", 2);
@@ -289,7 +289,7 @@ START_TEST(test_uart_printf_formats)
     ck_assert_str_eq(uart_buf, "0012");
 
     reset_uart_buf();
-    uart_printf("%p", (void*)0x10);
+    uart_printf("%p", (void*)(uintptr_t)0x10);
     ck_assert_str_eq(uart_buf, "0x10");
 
     reset_uart_buf();