From 89ef4b70b8b6a04a911da8ef94c2124fab031032 Mon Sep 17 00:00:00 2001
From: Daniel Hirt <daniel.hirt@samsung.com>
Date: Sat, 21 Nov 2015 12:39:00 +0200
Subject: [PATCH] Eina unicode: add eina_unicode_unicode_to_utf8_range

Required some special treatment to get words (substring) out of an
input Unicode string to a utf8 one. This saves the trouble converting
the whole string: you input an offset in the Eina_Unicode array, and
provide the required length. That's is, now you can extract words and
whatnot in utf8 form.

To save code I wrapped the original one to get the whole length.
---
 src/lib/eina/eina_unicode.c     | 14 +++++++++-----
 src/lib/eina/eina_unicode.h     | 11 +++++++++++
 src/tests/eina/eina_test_ustr.c | 17 +++++++++++++++++
 3 files changed, 37 insertions(+), 5 deletions(-)

diff --git a/src/lib/eina/eina_unicode.c b/src/lib/eina/eina_unicode.c
index c8fddd0576..adec87a477 100644
--- a/src/lib/eina/eina_unicode.c
+++ b/src/lib/eina/eina_unicode.c
@@ -341,21 +341,20 @@ eina_unicode_utf8_to_unicode(const char *utf, int *_len)
 }
 
 EAPI char *
-eina_unicode_unicode_to_utf8(const Eina_Unicode *uni, int *_len)
+eina_unicode_unicode_to_utf8_range(const Eina_Unicode *uni, int ulen, int *_len)
 {
    char *buf, *buf2;
    const Eina_Unicode *uind;
    char *ind;
-   int ulen, len;
+   int i, len;
 
    EINA_SAFETY_ON_NULL_RETURN_VAL(uni, NULL);
 
-   ulen = eina_unicode_strlen(uni);
    buf = malloc((ulen + 1) * EINA_UNICODE_UTF8_BYTES_PER_CHAR);
    if (!buf) return NULL;
 
    len = 0;
-   for (uind = uni, ind = buf ; *uind ; uind++)
+   for (uind = uni, ind = buf, i = 0 ; *uind && (i < ulen) ; uind++, i++)
      {
         if (*uind <= 0x7F) /* 1 byte char */
           {
@@ -424,5 +423,10 @@ eina_unicode_unicode_to_utf8(const Eina_Unicode *uni, int *_len)
    return buf2;
 }
 
+EAPI char *
+eina_unicode_unicode_to_utf8(const Eina_Unicode *uni, int *_len)
+{
+   int len = eina_unicode_strlen(uni);
 
-
+   return eina_unicode_unicode_to_utf8_range(uni, len, _len);
+}
diff --git a/src/lib/eina/eina_unicode.h b/src/lib/eina/eina_unicode.h
index e58b8532d2..7bf4f83484 100644
--- a/src/lib/eina/eina_unicode.h
+++ b/src/lib/eina/eina_unicode.h
@@ -178,6 +178,17 @@ EAPI int eina_unicode_utf8_get_len(const char *buf) EINA_ARG_NONNULL(1);
  */
 EAPI Eina_Unicode *eina_unicode_utf8_to_unicode(const char *utf, int *_len) EINA_WARN_UNUSED_RESULT EINA_ARG_NONNULL(1) EINA_MALLOC;
 
+/**
+ * Converts an Eina_Unicode string to a newly allocated utf-8 substring at given length.
+ *
+ * @param uni the Eina_Unicode string
+ * @param ulen the length in the unicode string to convert.
+ * @param _len the length byte length of the return utf8 substring.
+ * @return the newly allocated utf-8 substring.
+ * @since 1.17
+ */
+EAPI char * eina_unicode_unicode_to_utf8_range(const Eina_Unicode *uni, int ulen, int *_len) EINA_WARN_UNUSED_RESULT EINA_ARG_NONNULL(1) EINA_MALLOC;
+
 /**
  * Converts an Eina_Unicode string to a newly allocated utf-8 string.
  *
diff --git a/src/tests/eina/eina_test_ustr.c b/src/tests/eina/eina_test_ustr.c
index f9c28d3f80..fb36fd9013 100644
--- a/src/tests/eina/eina_test_ustr.c
+++ b/src/tests/eina/eina_test_ustr.c
@@ -585,6 +585,10 @@ START_TEST(eina_unicode_utf8_conversion)
    char c_in[] = "\xD7\x90""\xEF\xB7\xB6""\x80""\xF0\x9F\x91\x99"
       "\xFB\xBF\xBF\xBF\xBF""\xFD\xBF\xBF\xBF\xBF\xBF""abc";
    char *c_out;
+
+   /* Substring of c_in (offset = 2, length = 3) */
+   char c_sub[] = "\x80""\xF0\x9F\x91\x99""\xFB\xBF\xBF\xBF\xBF";
+   char *c_sub_out;
    int len;
 
    eina_init();
@@ -597,6 +601,19 @@ START_TEST(eina_unicode_utf8_conversion)
    fail_if((len != 24) || strcmp(c_in, c_out));
    free(c_out);
 
+   /* Range conversion */
+   c_sub_out = eina_unicode_unicode_to_utf8_range(uni_in + 2, 3, &len);
+   ck_assert_int_eq(len, 10);
+   ck_assert_str_eq(c_sub, c_sub_out);
+
+   c_sub_out = eina_unicode_unicode_to_utf8_range(uni_in, 100, &len);
+   ck_assert_int_eq(len, 24);
+   ck_assert_str_eq(c_in, c_sub_out);
+
+   c_sub_out = eina_unicode_unicode_to_utf8_range(uni_in, 0, &len);
+   ck_assert_int_eq(len, 0);
+   ck_assert_str_eq("", c_sub_out);
+
    eina_shutdown();
 }
 END_TEST