Squashed 'third_party/git/' content from commit cb71568594

git-subtree-dir: third_party/git
git-subtree-split: cb715685942260375e1eb8153b0768a376e4ece7

1 files changed, 193 insertions, 0 deletions

diff --git a/versioncmp.c b/versioncmp.c
new file mode 100644
index 0000000000..069ee94a4d
--- /dev/null
+++ b/versioncmp.c
@@ -0,0 +1,193 @@
+#include "cache.h"
+#include "config.h"
+#include "string-list.h"
+
+/*
+ * versioncmp(): copied from string/strverscmp.c in glibc commit
+ * ee9247c38a8def24a59eb5cfb7196a98bef8cfdc, reformatted to Git coding
+ * style. The implementation is under LGPL-2.1 and Git relicenses it
+ * to GPLv2.
+ */
+
+/*
+ * states: S_N: normal, S_I: comparing integral part, S_F: comparing
+ * fractionnal parts, S_Z: idem but with leading Zeroes only
+ */
+#define  S_N    0x0
+#define  S_I    0x3
+#define  S_F    0x6
+#define  S_Z    0x9
+
+/* result_type: CMP: return diff; LEN: compare using len_diff/diff */
+#define  CMP    2
+#define  LEN    3
+
+static const struct string_list *prereleases;
+static int initialized;
+
+struct suffix_match {
+	int conf_pos;
+	int start;
+	int len;
+};
+
+static void find_better_matching_suffix(const char *tagname, const char *suffix,
+					int suffix_len, int start, int conf_pos,
+					struct suffix_match *match)
+{
+	/*
+	 * A better match either starts earlier or starts at the same offset
+	 * but is longer.
+	 */
+	int end = match->len < suffix_len ? match->start : match->start-1;
+	int i;
+	for (i = start; i <= end; i++)
+		if (starts_with(tagname + i, suffix)) {
+			match->conf_pos = conf_pos;
+			match->start = i;
+			match->len = suffix_len;
+			break;
+		}
+}
+
+/*
+ * off is the offset of the first different character in the two strings
+ * s1 and s2. If either s1 or s2 contains a prerelease suffix containing
+ * that offset or a suffix ends right before that offset, then that
+ * string will be forced to be on top.
+ *
+ * If both s1 and s2 contain a (different) suffix around that position,
+ * their order is determined by the order of those two suffixes in the
+ * configuration.
+ * If any of the strings contains more than one different suffixes around
+ * that position, then that string is sorted according to the contained
+ * suffix which starts at the earliest offset in that string.
+ * If more than one different contained suffixes start at that earliest
+ * offset, then that string is sorted according to the longest of those
+ * suffixes.
+ *
+ * Return non-zero if *diff contains the return value for versioncmp()
+ */
+static int swap_prereleases(const char *s1,
+			    const char *s2,
+			    int off,
+			    int *diff)
+{
+	int i;
+	struct suffix_match match1 = { -1, off, -1 };
+	struct suffix_match match2 = { -1, off, -1 };
+
+	for (i = 0; i < prereleases->nr; i++) {
+		const char *suffix = prereleases->items[i].string;
+		int start, suffix_len = strlen(suffix);
+		if (suffix_len < off)
+			start = off - suffix_len;
+		else
+			start = 0;
+		find_better_matching_suffix(s1, suffix, suffix_len, start,
+					    i, &match1);
+		find_better_matching_suffix(s2, suffix, suffix_len, start,
+					    i, &match2);
+	}
+	if (match1.conf_pos == -1 && match2.conf_pos == -1)
+		return 0;
+	if (match1.conf_pos == match2.conf_pos)
+		/* Found the same suffix in both, e.g. "-rc" in "v1.0-rcX"
+		 * and "v1.0-rcY": the caller should decide based on "X"
+		 * and "Y". */
+		return 0;
+
+	if (match1.conf_pos >= 0 && match2.conf_pos >= 0)
+		*diff = match1.conf_pos - match2.conf_pos;
+	else if (match1.conf_pos >= 0)
+		*diff = -1;
+	else /* if (match2.conf_pos >= 0) */
+		*diff = 1;
+	return 1;
+}
+
+/*
+ * Compare S1 and S2 as strings holding indices/version numbers,
+ * returning less than, equal to or greater than zero if S1 is less
+ * than, equal to or greater than S2 (for more info, see the texinfo
+ * doc).
+ */
+
+int versioncmp(const char *s1, const char *s2)
+{
+	const unsigned char *p1 = (const unsigned char *) s1;
+	const unsigned char *p2 = (const unsigned char *) s2;
+	unsigned char c1, c2;
+	int state, diff;
+
+	/*
+	 * Symbol(s)    0       [1-9]   others
+	 * Transition   (10) 0  (01) d  (00) x
+	 */
+	static const uint8_t next_state[] = {
+		/* state    x    d    0  */
+		/* S_N */  S_N, S_I, S_Z,
+		/* S_I */  S_N, S_I, S_I,
+		/* S_F */  S_N, S_F, S_F,
+		/* S_Z */  S_N, S_F, S_Z
+	};
+
+	static const int8_t result_type[] = {
+		/* state   x/x  x/d  x/0  d/x  d/d  d/0  0/x  0/d  0/0  */
+
+		/* S_N */  CMP, CMP, CMP, CMP, LEN, CMP, CMP, CMP, CMP,
+		/* S_I */  CMP, -1,  -1,  +1,  LEN, LEN, +1,  LEN, LEN,
+		/* S_F */  CMP, CMP, CMP, CMP, CMP, CMP, CMP, CMP, CMP,
+		/* S_Z */  CMP, +1,  +1,  -1,  CMP, CMP, -1,  CMP, CMP
+	};
+
+	if (p1 == p2)
+		return 0;
+
+	c1 = *p1++;
+	c2 = *p2++;
+	/* Hint: '0' is a digit too.  */
+	state = S_N + ((c1 == '0') + (isdigit (c1) != 0));
+
+	while ((diff = c1 - c2) == 0) {
+		if (c1 == '\0')
+			return diff;
+
+		state = next_state[state];
+		c1 = *p1++;
+		c2 = *p2++;
+		state += (c1 == '0') + (isdigit (c1) != 0);
+	}
+
+	if (!initialized) {
+		const struct string_list *deprecated_prereleases;
+		initialized = 1;
+		prereleases = git_config_get_value_multi("versionsort.suffix");
+		deprecated_prereleases = git_config_get_value_multi("versionsort.prereleasesuffix");
+		if (prereleases) {
+			if (deprecated_prereleases)
+				warning("ignoring versionsort.prereleasesuffix because versionsort.suffix is set");
+		} else
+			prereleases = deprecated_prereleases;
+	}
+	if (prereleases && swap_prereleases(s1, s2, (const char *) p1 - s1 - 1,
+					    &diff))
+		return diff;
+
+	state = result_type[state * 3 + (((c2 == '0') + (isdigit (c2) != 0)))];
+
+	switch (state) {
+	case CMP:
+		return diff;
+
+	case LEN:
+		while (isdigit (*p1++))
+			if (!isdigit (*p2++))
+				return 1;
+
+		return isdigit (*p2) ? -1 : diff;
+
+	default:
+		return state;
+	}
+}