--- /dev/null
+/* c-strcasecmp.c -- case insensitive string comparator in C locale
+ Copyright (C) 1998-1999, 2005-2006, 2009-2021 Free Software Foundation, Inc.
+
+ Character handling in C locale.
+ Copyright (C) 2000-2003, 2006, 2008-2021 Free Software Foundation, Inc.
+
+ Stripped down copy of gnulib c-ctype and c-strcasecmp modules for
+ conditional fallback use.
+
+ This program is free software; you can redistribute it and/or modify
+ it under the terms of the GNU General Public License as published by
+ the Free Software Foundation; either version 2, or (at your option)
+ any later version.
+
+ This program is distributed in the hope that it will be useful,
+ but WITHOUT ANY WARRANTY; without even the implied warranty of
+ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ GNU General Public License for more details.
+
+ You should have received a copy of the GNU General Public License
+ along with this program; if not, see <https://www.gnu.org/licenses/>. */
+
+#include <config.h>
+#include <limits.h>
+
+#undef HAVE_G_ASCII_STRCASECMP
+#include "util.h"
+
+/* The functions defined in this file assume the "C" locale and a character
+ set without diacritics (ASCII-US or EBCDIC-US or something like that).
+ Even if the "C" locale on a particular system is an extension of the ASCII
+ character set (like on BeOS, where it is UTF-8, or on AmigaOS, where it
+ is ISO-8859-1), the functions in this file recognize only the ASCII
+ characters. */
+
+#if (' ' == 32) && ('!' == 33) && ('"' == 34) && ('#' == 35) \
+ && ('%' == 37) && ('&' == 38) && ('\'' == 39) && ('(' == 40) \
+ && (')' == 41) && ('*' == 42) && ('+' == 43) && (',' == 44) \
+ && ('-' == 45) && ('.' == 46) && ('/' == 47) && ('0' == 48) \
+ && ('1' == 49) && ('2' == 50) && ('3' == 51) && ('4' == 52) \
+ && ('5' == 53) && ('6' == 54) && ('7' == 55) && ('8' == 56) \
+ && ('9' == 57) && (':' == 58) && (';' == 59) && ('<' == 60) \
+ && ('=' == 61) && ('>' == 62) && ('?' == 63) && ('A' == 65) \
+ && ('B' == 66) && ('C' == 67) && ('D' == 68) && ('E' == 69) \
+ && ('F' == 70) && ('G' == 71) && ('H' == 72) && ('I' == 73) \
+ && ('J' == 74) && ('K' == 75) && ('L' == 76) && ('M' == 77) \
+ && ('N' == 78) && ('O' == 79) && ('P' == 80) && ('Q' == 81) \
+ && ('R' == 82) && ('S' == 83) && ('T' == 84) && ('U' == 85) \
+ && ('V' == 86) && ('W' == 87) && ('X' == 88) && ('Y' == 89) \
+ && ('Z' == 90) && ('[' == 91) && ('\\' == 92) && (']' == 93) \
+ && ('^' == 94) && ('_' == 95) && ('a' == 97) && ('b' == 98) \
+ && ('c' == 99) && ('d' == 100) && ('e' == 101) && ('f' == 102) \
+ && ('g' == 103) && ('h' == 104) && ('i' == 105) && ('j' == 106) \
+ && ('k' == 107) && ('l' == 108) && ('m' == 109) && ('n' == 110) \
+ && ('o' == 111) && ('p' == 112) && ('q' == 113) && ('r' == 114) \
+ && ('s' == 115) && ('t' == 116) && ('u' == 117) && ('v' == 118) \
+ && ('w' == 119) && ('x' == 120) && ('y' == 121) && ('z' == 122) \
+ && ('{' == 123) && ('|' == 124) && ('}' == 125) && ('~' == 126)
+/* The character set is ASCII or one of its variants or extensions, not EBCDIC.
+ Testing the value of '\n' and '\r' is not relevant. */
+# define C_CTYPE_ASCII 1
+#elif ! (' ' == '\x40' && '0' == '\xf0' \
+ && 'A' == '\xc1' && 'J' == '\xd1' && 'S' == '\xe2' \
+ && 'a' == '\x81' && 'j' == '\x91' && 's' == '\xa2')
+# error "Only ASCII and EBCDIC are supported"
+#endif
+
+#if 'A' < 0
+# error "EBCDIC and char is signed -- not supported"
+#endif
+
+/* Cases for lowercase hex letters, and lowercase letters, all offset by N. */
+
+#define C_CTYPE_LOWER_A_THRU_F_N(N) \
+ case 'a' + (N): case 'b' + (N): case 'c' + (N): case 'd' + (N): \
+ case 'e' + (N): case 'f' + (N)
+#define C_CTYPE_LOWER_N(N) \
+ C_CTYPE_LOWER_A_THRU_F_N(N): \
+ case 'g' + (N): case 'h' + (N): case 'i' + (N): case 'j' + (N): \
+ case 'k' + (N): case 'l' + (N): case 'm' + (N): case 'n' + (N): \
+ case 'o' + (N): case 'p' + (N): case 'q' + (N): case 'r' + (N): \
+ case 's' + (N): case 't' + (N): case 'u' + (N): case 'v' + (N): \
+ case 'w' + (N): case 'x' + (N): case 'y' + (N): case 'z' + (N)
+
+#define C_CTYPE_LOWER C_CTYPE_LOWER_N(0)
+#define C_CTYPE_UPPER C_CTYPE_LOWER_N ('A' - 'a')
+
+
+/* Function definitions. */
+
+/* Unlike the functions in <ctype.h>, which require an argument in the range
+ of the 'unsigned char' type, the functions here operate on values that are
+ in the 'unsigned char' range or in the 'char' range. In other words,
+ when you have a 'char' value, you need to cast it before using it as
+ argument to a <ctype.h> function:
+
+ const char *s = ...;
+ if (isalpha ((unsigned char) *s)) ...
+
+ but you don't need to cast it for the functions defined in this file:
+
+ const char *s = ...;
+ if (c_isalpha (*s)) ...
+ */
+
+static int c_tolower(int c)
+{
+ switch (c) {
+ C_CTYPE_UPPER:
+ return c - 'A' + 'a';
+ default:
+ return c;
+ }
+}
+
+static int c_toupper(int c)
+{
+ switch (c) {
+ C_CTYPE_LOWER:
+ return c - 'a' + 'A';
+ default:
+ return c;
+ }
+}
+
+char *gob_strup(char *str)
+{
+ char *s;
+
+ for (s = str; *s; s++)
+ *s = c_toupper(*s);
+
+ return str;
+}
+
+char *gob_strdown(char *str)
+{
+ char *s;
+
+ for (s = str; *s; s++)
+ *s = c_tolower(*s);
+
+ return str;
+}
+
+int gob_strcasecmp(const char *s1, const char *s2)
+{
+ register const unsigned char *p1 = (const unsigned char *)s1;
+ register const unsigned char *p2 = (const unsigned char *)s2;
+ unsigned char c1, c2;
+
+ if (p1 == p2)
+ return 0;
+
+ do {
+ c1 = c_tolower (*p1);
+ c2 = c_tolower (*p2);
+
+ if (c1 == '\0')
+ break;
+
+ ++p1;
+ ++p2;
+ } while (c1 == c2);
+
+ if (UCHAR_MAX <= INT_MAX) {
+ return c1 - c2;
+ } else {
+ /*
+ * On machines where 'char' and 'int' are types of the
+ * same size, the difference of two 'unsigned char' values
+ * - including the sign bit - doesn't fit in an 'int'.
+ */
+ return _GL_CMP (c1, c2);
+ }
+}