Case folding fixes (#133)

* Fixes allowing for “Full” folding and NFKC_CaseFold compliance.

* Only include C (Common) and F (Full) foldings from CaseFolding.txt. Removed S (Simple) since F & S are specified to be exclusive.
* Extend UTF8PROC_IGNORE to also ignore unassigned codepoints (such as \u2065) which are specified as being discarded by NFKC_CF.

* Document the changes to UTF8PROC_IGNORE in header.

* Add NFKC_CF helper function with documentation.

* restore old IGNORE behavior, add UTF8PROC_STRIPNA, rename to utf8proc_NFKC_Casefold, add a test

* success message

* test that IGNORE does not strip NA

* data update

* NFKC_Casefold shouldn't strip NA

data/data_generator.rb

@@ -104,7 +104,7 @@ $excl_version = $excl_version.chomp.split("\n").collect { |e| e.hex }
 $case_folding_string = File.open("CaseFolding.txt", :encoding => 'utf-8').read
 $case_folding = {}
 $case_folding_string.chomp.split("\n").each do |line|
-  next unless line =~ /([0-9A-F]+); [CFS]; ([0-9A-F ]+);/i
+  next unless line =~ /([0-9A-F]+); [CF]; ([0-9A-F ]+);/i
   $case_folding[$1.hex] = $2.split(" ").collect { |e| e.hex }
 end
 

test/custom.c

@@ -23,5 +23,6 @@ int main(void)
     check(strlen((char*) output) == 6, "incorrect output length");
     check(!memcmp(correct, output, 7), "incorrect output data");
     free(output);
+    printf("map_custom tests SUCCEEDED.\n");
     return 0;
 }

test/misc.c

@@ -19,9 +19,28 @@ static void issue128(void) /* #128 */
     free(nfd_out); free(nfc_out);
 }
 
+static void issue102(void) /* #128 */
+{
+    utf8proc_uint8_t input[] = {0x58, 0xe2, 0x81, 0xa5, 0x45, 0xcc, 0x80, 0xc2, 0xad, 0xe1, 0xb4, 0xac, 0x00}; /* "X\u2065E\u0300\u00ad\u1d2c" */
+    utf8proc_uint8_t stripna[] = {0x78, 0xc3, 0xa8, 0x61, 0x00}; /* "x\u00e8a" */
+    utf8proc_uint8_t correct[] = {0x78, 0xe2, 0x81, 0xa5, 0xc3, 0xa8, 0x61, 0x00}; /* "x\u2065\u00e8a" */
+    utf8proc_uint8_t *output;
+    utf8proc_map(input, 0, &output, UTF8PROC_NULLTERM | UTF8PROC_STABLE |
+        UTF8PROC_COMPOSE | UTF8PROC_COMPAT | UTF8PROC_CASEFOLD | UTF8PROC_IGNORE | UTF8PROC_STRIPNA);
+    printf("NFKC_Casefold \"%s\" -> \"%s\" vs. \"%s\"\n", (char*)input, (char*)output, (char*)stripna);
+    check(strlen((char*) output) == 4, "incorrect NFKC_Casefold+stripna length");
+    check(!memcmp(stripna, output, 5), "incorrect NFKC_Casefold+stripna data");
+    free(output);
+    output = utf8proc_NFKC_Casefold(input);
+    printf("NFKC_Casefold \"%s\" -> \"%s\" vs. \"%s\"\n", (char*)input, (char*)output, (char*)correct);
+    check(strlen((char*) output) == 7, "incorrect NFKC_Casefold length");
+    check(!memcmp(correct, output, 8), "incorrect NFKC_Casefold data");
+}
+
 int main(void)
 {
     issue128();
+    issue102();
     printf("Misc tests SUCCEEDED.\n");
     return 0;
 }

utf8proc.c

@@ -423,6 +423,9 @@ UTF8PROC_DLLEXPORT utf8proc_ssize_t utf8proc_decompose_char(utf8proc_int32_t uc,
   if (options & UTF8PROC_IGNORE) {
     if (property->ignorable) return 0;
   }
+  if (options & UTF8PROC_STRIPNA) {
+    if (!category) return 0;
+  }
   if (options & UTF8PROC_LUMP) {
     if (category == UTF8PROC_CATEGORY_ZS) utf8proc_decompose_lump(0x0020);
     if (uc == 0x2018 || uc == 0x2019 || uc == 0x02BC || uc == 0x02C8)
@@ -752,3 +755,10 @@ UTF8PROC_DLLEXPORT utf8proc_uint8_t *utf8proc_NFKC(const utf8proc_uint8_t *str)
     UTF8PROC_COMPOSE | UTF8PROC_COMPAT);
   return retval;
 }
+
+UTF8PROC_DLLEXPORT utf8proc_uint8_t *utf8proc_NFKC_Casefold(const utf8proc_uint8_t *str) {
+  utf8proc_uint8_t *retval;
+  utf8proc_map(str, 0, &retval, UTF8PROC_NULLTERM | UTF8PROC_STABLE |
+    UTF8PROC_COMPOSE | UTF8PROC_COMPAT | UTF8PROC_CASEFOLD | UTF8PROC_IGNORE);
+  return retval;
+}

utf8proc.h

@@ -213,6 +213,10 @@ typedef enum {
    *       @ref UTF8PROC_DECOMPOSE
    */
   UTF8PROC_STRIPMARK = (1<<13),
+  /**
+   * Strip unassigned codepoints.
+   */
+  UTF8PROC_STRIPNA    = (1<<14),
 } utf8proc_option_t;
 
 /** @name Error codes
@@ -469,6 +473,7 @@ UTF8PROC_DLLEXPORT const utf8proc_property_t *utf8proc_get_property(utf8proc_int
  * - @ref UTF8PROC_CHARBOUND - insert 0xFF bytes before each grapheme cluster
  * - @ref UTF8PROC_LUMP      - lump certain different codepoints together
  * - @ref UTF8PROC_STRIPMARK - remove all character marks
+ * - @ref UTF8PROC_STRIPNA   - remove unassigned codepoints
  * @param last_boundclass
  * Pointer to an integer variable containing
  * the previous codepoint's boundary class if the @ref UTF8PROC_CHARBOUND
@@ -680,8 +685,8 @@ UTF8PROC_DLLEXPORT utf8proc_ssize_t utf8proc_map_custom(
 
 /** @name Unicode normalization
  *
- * Returns a pointer to newly allocated memory of a NFD, NFC, NFKD or NFKC
- * normalized version of the null-terminated string `str`.  These
+ * Returns a pointer to newly allocated memory of a NFD, NFC, NFKD, NFKC or
+ * NFKC_Casefold normalized version of the null-terminated string `str`.  These
  * are shortcuts to calling @ref utf8proc_map with @ref UTF8PROC_NULLTERM
  * combined with @ref UTF8PROC_STABLE and flags indicating the normalization.
  */
@@ -694,6 +699,11 @@ UTF8PROC_DLLEXPORT utf8proc_uint8_t *utf8proc_NFC(const utf8proc_uint8_t *str);
 UTF8PROC_DLLEXPORT utf8proc_uint8_t *utf8proc_NFKD(const utf8proc_uint8_t *str);
 /** NFKC normalization (@ref UTF8PROC_COMPOSE and @ref UTF8PROC_COMPAT). */
 UTF8PROC_DLLEXPORT utf8proc_uint8_t *utf8proc_NFKC(const utf8proc_uint8_t *str);
+/**
+ * NFKC_Casefold normalization (@ref UTF8PROC_COMPOSE and @ref UTF8PROC_COMPAT
+ * and @ref UTF8PROC_CASEFOLD and @ref UTF8PROC_IGNORE).
+ **/
+UTF8PROC_DLLEXPORT utf8proc_uint8_t *utf8proc_NFKC_Casefold(const utf8proc_uint8_t *str);
 /** @} */
 
 #ifdef __cplusplus