1 files changed, 267 insertions, 0 deletions
diff --git a/lib/strutil/filevercmp.c b/lib/strutil/filevercmp.c
new file mode 100644
index 0000000..c0a28dd
--- /dev/null
+++ b/lib/strutil/filevercmp.c
@@ -0,0 +1,267 @@
+/*
+   Copyright (C) 1995 Ian Jackson <iwj10@cus.cam.ac.uk>
+   Copyright (C) 2001 Anthony Towns <aj@azure.humbug.org.au>
+   Copyright (C) 2008-2022 Free Software Foundation, Inc.
+
+   This file is free software: you can redistribute it and/or modify
+   it under the terms of the GNU Lesser General Public License as
+   published by the Free Software Foundation, either version 3 of the
+   License, or (at your option) any later version.
+
+   This file 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 Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General Public License
+   along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
+
+#include <config.h>
+
+#include <stdlib.h>
+#include <limits.h>
+
+#include "lib/strutil.h"
+
+/*** global variables ****************************************************************************/
+
+/*** file scope macro definitions ****************************************************************/
+
+/*** file scope type declarations ****************************************************************/
+
+/*** forward declarations (file scope functions) *************************************************/
+
+/*** file scope variables ************************************************************************/
+
+/* --------------------------------------------------------------------------------------------- */
+/*** file scope functions ************************************************************************/
+/* --------------------------------------------------------------------------------------------- */
+
+/* Return the length of a prefix of @s that corresponds to the suffix defined by this extended
+ * regular expression in the C locale: (\.[A-Za-z~][A-Za-z0-9~]*)*$
+ *
+ * Use the longest suffix matching this regular expression, except do not use all of s as a suffix
+ * if s is nonempty.
+ *
+ * If *len is -1, s is a string; set *lem to s's length.
+ * Otherwise, *len should be nonnegative, s is a char array, and *len does not change.
+ */
+static ssize_t
+file_prefixlen (const char *s, ssize_t * len)
+{
+    size_t n = (size_t) (*len); /* SIZE_MAX if N == -1 */
+    size_t i = 0;
+    size_t prefixlen = 0;
+
+    while (TRUE)
+    {
+        gboolean done;
+
+        if (*len < 0)
+            done = s[i] == '\0';
+        else
+            done = i == n;
+
+        if (done)
+        {
+            *len = (ssize_t) i;
+            return (ssize_t) prefixlen;
+        }
+
+        i++;
+        prefixlen = i;
+
+        while (i + 1 < n && s[i] == '.' && (g_ascii_isalpha (s[i + 1]) || s[i + 1] == '~'))
+            for (i += 2; i < n && (g_ascii_isalnum (s[i]) || s[i] == '~'); i++)
+                ;
+    }
+}
+
+/* --------------------------------------------------------------------------------------------- */
+
+/* Return a version sort comparison value for @s's byte at position @pos.
+ *
+ * @param s a string
+ * @param pos a position in @s
+ * @param len a length of @s. If @pos == @len, sort before all non-'~' bytes.
+ */
+
+static int
+order (const char *s, size_t pos, size_t len)
+{
+    unsigned char c;
+
+    if (pos == len)
+        return (-1);
+
+    c = s[pos];
+
+    if (g_ascii_isdigit (c))
+        return 0;
+    if (g_ascii_isalpha (c))
+        return c;
+    if (c == '~')
+        return (-2);
+
+    g_assert (UCHAR_MAX <= (INT_MAX - 1 - 2) / 2);
+
+    return (int) c + UCHAR_MAX + 1;
+}
+
+/* --------------------------------------------------------------------------------------------- */
+
+/* Slightly modified verrevcmp function from dpkg
+ *
+ * This implements the algorithm for comparison of version strings
+ * specified by Debian and now widely adopted.  The detailed
+ * specification can be found in the Debian Policy Manual in the
+ * section on the 'Version' control field.  This version of the code
+ * implements that from s5.6.12 of Debian Policy v3.8.0.1
+ * https://www.debian.org/doc/debian-policy/ch-controlfields.html#s-f-Version
+ *
+ * @param s1 first char array to compare
+ * @param s1_len length of @s1
+ * @param s2 second char array to compare
+ * @param s2_len length of @s2
+ *
+ * @return an integer less than, equal to, or greater than zero, if @s1 is <, == or > than @s2.
+ */
+static int
+verrevcmp (const char *s1, ssize_t s1_len, const char *s2, ssize_t s2_len)
+{
+    ssize_t s1_pos = 0;
+    ssize_t s2_pos = 0;
+
+    while (s1_pos < s1_len || s2_pos < s2_len)
+    {
+        int first_diff = 0;
+
+        while ((s1_pos < s1_len && !g_ascii_isdigit (s1[s1_pos]))
+               || (s2_pos < s2_len && !g_ascii_isdigit (s2[s2_pos])))
+        {
+            int s1_c, s2_c;
+
+            s1_c = order (s1, s1_pos, s1_len);
+            s2_c = order (s2, s2_pos, s2_len);
+
+            if (s1_c != s2_c)
+                return (s1_c - s2_c);
+
+            s1_pos++;
+            s2_pos++;
+        }
+
+        while (s1_pos < s1_len && s1[s1_pos] == '0')
+            s1_pos++;
+        while (s2_pos < s2_len && s2[s2_pos] == '0')
+            s2_pos++;
+
+        while (s1_pos < s1_len && s2_pos < s2_len
+               && g_ascii_isdigit (s1[s1_pos]) && g_ascii_isdigit (s2[s2_pos]))
+        {
+            if (first_diff == 0)
+                first_diff = s1[s1_pos] - s2[s2_pos];
+
+            s1_pos++;
+            s2_pos++;
+        }
+
+        if (s1_pos < s1_len && g_ascii_isdigit (s1[s1_pos]))
+            return 1;
+        if (s2_pos < s2_len && g_ascii_isdigit (s2[s2_pos]))
+            return (-1);
+        if (first_diff != 0)
+            return first_diff;
+    }
+
+    return 0;
+}
+
+/* --------------------------------------------------------------------------------------------- */
+/*** public functions ****************************************************************************/
+/* --------------------------------------------------------------------------------------------- */
+
+/* Compare version strings.
+ *
+ * @param s1 first string to compare
+ * @param s2 second string to compare
+ *
+ * @return an integer less than, equal to, or greater than zero, if @s1 is <, == or > than @s2.
+ */
+int
+filevercmp (const char *s1, const char *s2)
+{
+    return filenvercmp (s1, -1, s2, -1);
+}
+
+/* --------------------------------------------------------------------------------------------- */
+/* Compare version strings.
+ *
+ * @param a first string to compare
+ * @param alen length of @a or (-1)
+ * @param b second string to compare
+ * @param blen length of @b or (-1)
+ *
+ * @return an integer less than, equal to, or greater than zero, if @s1 is <, == or > than @s2.
+ */
+int
+filenvercmp (const char *a, ssize_t alen, const char *b, ssize_t blen)
+{
+    gboolean aempty, bempty;
+    ssize_t aprefixlen, bprefixlen;
+    gboolean one_pass_only;
+    int result;
+
+    /* Special case for empty versions. */
+    aempty = alen < 0 ? a[0] == '\0' : alen == 0;
+    bempty = blen < 0 ? b[0] == '\0' : blen == 0;
+
+    if (aempty)
+        return (bempty ? 0 : -1);
+    if (bempty)
+        return 1;
+
+    /* Special cases for leading ".": "." sorts first, then "..", then other names with leading ".",
+       then other names. */
+    if (a[0] == '.')
+    {
+        gboolean adot, bdot;
+        gboolean adotdot, bdotdot;
+
+        if (b[0] != '.')
+            return (-1);
+
+        adot = alen < 0 ? a[1] == '\0' : alen == 1;
+        bdot = blen < 0 ? b[1] == '\0' : blen == 1;
+
+        if (adot)
+            return (bdot ? 0 : -1);
+        if (bdot)
+            return 1;
+
+        adotdot = a[1] == '.' && (alen < 0 ? a[2] == '\0' : alen == 2);
+        bdotdot = b[1] == '.' && (blen < 0 ? b[2] == '\0' : blen == 2);
+        if (adotdot)
+            return (bdotdot ? 0 : -1);
+        if (bdotdot)
+            return 1;
+    }
+    else if (b[0] == '.')
+        return 1;
+
+    /* Cut file suffixes. */
+    aprefixlen = file_prefixlen (a, &alen);
+    bprefixlen = file_prefixlen (b, &blen);
+
+    /* If both suffixes are empty, a second pass would return the same thing. */
+    one_pass_only = aprefixlen == alen && bprefixlen == blen;
+
+    result = verrevcmp (a, aprefixlen, b, bprefixlen);
+
+    /* Return the initial result if nonzero, or if no second pass is needed.
+       Otherwise, restore the suffixes and try again. */
+    return (result != 0 || one_pass_only ? result : verrevcmp (a, alen, b, blen));
+}
+
+/* --------------------------------------------------------------------------------------------- */