(svn r21343) -Add: Function that compares strings using case insensitive natural sort.

1 files changed, 42 insertions, 0 deletions

diff --git a/src/string.cpp b/src/string.cpp
index bad29649d..c3d6f5bc0 100644
--- a/src/string.cpp
+++ b/src/string.cpp
@@ -24,6 +24,13 @@
 #include <errno.h> // required by vsnprintf implementation for MSVC
 #endif
 
+#ifdef WITH_ICU
+/* Required by strnatcmp. */
+#include <unicode/ustring.h>
+#include "language.h"
+#include "gfx_func.h"
+#endif /* WITH_ICU */
+
 /**
  * Safer implementation of vsnprintf; same as vsnprintf except:
  * - last instead of size, i.e. replace sizeof with lastof.
@@ -463,3 +470,38 @@ char *strcasestr(const char *haystack, const char *needle)
 	return NULL;
 }
 #endif /* DEFINE_STRCASESTR */
+
+/**
+ * Compares two strings using case insensitive natural sort.
+ *
+ * @param s1 First string to compare.
+ * @param s2 Second string to compare.
+ * @return Less than zero if s1 < s2, zero if s1 == s2, greater than zero if s1 > s2.
+ */
+int strnatcmp(const char *s1, const char *s2)
+{
+#ifdef WITH_ICU
+	if (_current_collator != NULL) {
+		UErrorCode status = U_ZERO_ERROR;
+		int result;
+
+		/* We want to use the new faster method for ICU 4.2 and higher. */
+#if U_ICU_VERSION_MAJOR_NUM > 4 || (U_ICU_VERSION_MAJOR_NUM == 4 && U_ICU_VERSION_MINOR_NUM >= 2)
+		/* The StringPiece parameter gets implicitly constructed from the char *. */
+		result = _current_collator->compareUTF8(s1, s2, status);
+#else /* The following for 4.0 and lower. */
+		UChar buffer1[DRAW_STRING_BUFFER];
+		u_strFromUTF8Lenient(buffer1, lengthof(buffer1), NULL, s1, -1, &status);
+		UChar buffer2[DRAW_STRING_BUFFER];
+		u_strFromUTF8Lenient(buffer2, lengthof(buffer2), NULL, s2, -1, &status);
+
+		result = _current_collator->compare(buffer1, buffer2, status);
+#endif /* ICU version check. */
+		if (U_SUCCESS(status)) return result;
+	}
+
+#endif /* WITH_ICU */
+
+	/* Do a normal comparison if ICU is missing or if we cannot create a collator. */
+	return strcasecmp(s1, s2);
+}