Check in the pristine copy of ICU 4.6...

icu46/source/common/loclikely.cpp

+/*
+*******************************************************************************
+*
+*   Copyright (C) 1997-2010, International Business Machines
+*   Corporation and others.  All Rights Reserved.
+*
+*******************************************************************************
+*   file name:  loclikely.cpp
+*   encoding:   US-ASCII
+*   tab size:   8 (not used)
+*   indentation:4
+*
+*   created on: 2010feb25
+*   created by: Markus W. Scherer
+*
+*   Code for likely and minimized locale subtags, separated out from other .cpp files
+*   that then do not depend on resource bundle code and likely-subtags data.
+*/
+
+#include "unicode/utypes.h"
+#include "unicode/putil.h"
+#include "unicode/uloc.h"
+#include "unicode/ures.h"
+#include "cmemory.h"
+#include "cstring.h"
+#include "ulocimp.h"
+#include "ustr_imp.h"
+
+/**
+ * This function looks for the localeID in the likelySubtags resource.
+ *
+ * @param localeID The tag to find.
+ * @param buffer A buffer to hold the matching entry
+ * @param bufferLength The length of the output buffer
+ * @return A pointer to "buffer" if found, or a null pointer if not.
+ */
+static const char*  U_CALLCONV
+findLikelySubtags(const char* localeID,
+                  char* buffer,
+                  int32_t bufferLength,
+                  UErrorCode* err) {
+    const char* result = NULL;
+
+    if (!U_FAILURE(*err)) {
+        int32_t resLen = 0;
+        const UChar* s = NULL;
+        UErrorCode tmpErr = U_ZERO_ERROR;
+        UResourceBundle* subtags = ures_openDirect(NULL, "likelySubtags", &tmpErr);
+        if (U_SUCCESS(tmpErr)) {
+            s = ures_getStringByKey(subtags, localeID, &resLen, &tmpErr);
+
+            if (U_FAILURE(tmpErr)) {
+                /*
+                 * If a resource is missing, it's not really an error, it's
+                 * just that we don't have any data for that particular locale ID.
+                 */
+                if (tmpErr != U_MISSING_RESOURCE_ERROR) {
+                    *err = tmpErr;
+                }
+            }
+            else if (resLen >= bufferLength) {
+                /* The buffer should never overflow. */
+                *err = U_INTERNAL_PROGRAM_ERROR;
+            }
+            else {
+                u_UCharsToChars(s, buffer, resLen + 1);
+                result = buffer;
+            }
+
+            ures_close(subtags);
+        } else {
+            *err = tmpErr;
+        }
+    }
+
+    return result;
+}
+
+/**
+ * Append a tag to a buffer, adding the separator if necessary.  The buffer
+ * must be large enough to contain the resulting tag plus any separator
+ * necessary. The tag must not be a zero-length string.
+ *
+ * @param tag The tag to add.
+ * @param tagLength The length of the tag.
+ * @param buffer The output buffer.
+ * @param bufferLength The length of the output buffer.  This is an input/ouput parameter.
+ **/
+static void U_CALLCONV
+appendTag(
+    const char* tag,
+    int32_t tagLength,
+    char* buffer,
+    int32_t* bufferLength) {
+
+    if (*bufferLength > 0) {
+        buffer[*bufferLength] = '_';
+        ++(*bufferLength);
+    }
+
+    uprv_memmove(
+        &buffer[*bufferLength],
+        tag,
+        tagLength);
+
+    *bufferLength += tagLength;
+}
+
+/**
+ * These are the canonical strings for unknown languages, scripts and regions.
+ **/
+static const char* const unknownLanguage = "und";
+static const char* const unknownScript = "Zzzz";
+static const char* const unknownRegion = "ZZ";
+
+/**
+ * Create a tag string from the supplied parameters.  The lang, script and region
+ * parameters may be NULL pointers. If they are, their corresponding length parameters
+ * must be less than or equal to 0.
+ *
+ * If any of the language, script or region parameters are empty, and the alternateTags
+ * parameter is not NULL, it will be parsed for potential language, script and region tags
+ * to be used when constructing the new tag.  If the alternateTags parameter is NULL, or
+ * it contains no language tag, the default tag for the unknown language is used.
+ *
+ * If the length of the new string exceeds the capacity of the output buffer, 
+ * the function copies as many bytes to the output buffer as it can, and returns
+ * the error U_BUFFER_OVERFLOW_ERROR.
+ *
+ * If an illegal argument is provided, the function returns the error
+ * U_ILLEGAL_ARGUMENT_ERROR.
+ *
+ * Note that this function can return the warning U_STRING_NOT_TERMINATED_WARNING if
+ * the tag string fits in the output buffer, but the null terminator doesn't.
+ *
+ * @param lang The language tag to use.
+ * @param langLength The length of the language tag.
+ * @param script The script tag to use.
+ * @param scriptLength The length of the script tag.
+ * @param region The region tag to use.
+ * @param regionLength The length of the region tag.
+ * @param trailing Any trailing data to append to the new tag.
+ * @param trailingLength The length of the trailing data.
+ * @param alternateTags A string containing any alternate tags.
+ * @param tag The output buffer.
+ * @param tagCapacity The capacity of the output buffer.
+ * @param err A pointer to a UErrorCode for error reporting.
+ * @return The length of the tag string, which may be greater than tagCapacity, or -1 on error.
+ **/
+static int32_t U_CALLCONV
+createTagStringWithAlternates(
+    const char* lang,
+    int32_t langLength,
+    const char* script,
+    int32_t scriptLength,
+    const char* region,
+    int32_t regionLength,
+    const char* trailing,
+    int32_t trailingLength,
+    const char* alternateTags,
+    char* tag,
+    int32_t tagCapacity,
+    UErrorCode* err) {
+
+    if (U_FAILURE(*err)) {
+        goto error;
+    }
+    else if (tag == NULL ||
+             tagCapacity <= 0 ||
+             langLength >= ULOC_LANG_CAPACITY ||
+             scriptLength >= ULOC_SCRIPT_CAPACITY ||
+             regionLength >= ULOC_COUNTRY_CAPACITY) {
+        goto error;
+    }
+    else {
+        /**
+         * ULOC_FULLNAME_CAPACITY will provide enough capacity
+         * that we can build a string that contains the language,
+         * script and region code without worrying about overrunning
+         * the user-supplied buffer.
+         **/
+        char tagBuffer[ULOC_FULLNAME_CAPACITY];
+        int32_t tagLength = 0;
+        int32_t capacityRemaining = tagCapacity;
+        UBool regionAppended = FALSE;
+
+        if (langLength > 0) {
+            appendTag(
+                lang,
+                langLength,
+                tagBuffer,
+                &tagLength);
+        }
+        else if (alternateTags == NULL) {
+            /*
+             * Append the value for an unknown language, if
+             * we found no language.
+             */
+            appendTag(
+                unknownLanguage,
+                (int32_t)uprv_strlen(unknownLanguage),
+                tagBuffer,
+                &tagLength);
+        }
+        else {
+            /*
+             * Parse the alternateTags string for the language.
+             */
+            char alternateLang[ULOC_LANG_CAPACITY];
+            int32_t alternateLangLength = sizeof(alternateLang);
+
+            alternateLangLength =
+                uloc_getLanguage(
+                    alternateTags,
+                    alternateLang,
+                    alternateLangLength,
+                    err);
+            if(U_FAILURE(*err) ||
+                alternateLangLength >= ULOC_LANG_CAPACITY) {
+                goto error;
+            }
+            else if (alternateLangLength == 0) {
+                /*
+                 * Append the value for an unknown language, if
+                 * we found no language.
+                 */
+                appendTag(
+                    unknownLanguage,
+                    (int32_t)uprv_strlen(unknownLanguage),
+                    tagBuffer,
+                    &tagLength);
+            }
+            else {
+                appendTag(
+                    alternateLang,
+                    alternateLangLength,
+                    tagBuffer,
+                    &tagLength);
+            }
+        }
+
+        if (scriptLength > 0) {
+            appendTag(
+                script,
+                scriptLength,
+                tagBuffer,
+                &tagLength);
+        }
+        else if (alternateTags != NULL) {
+            /*
+             * Parse the alternateTags string for the script.
+             */
+            char alternateScript[ULOC_SCRIPT_CAPACITY];
+
+            const int32_t alternateScriptLength =
+                uloc_getScript(
+                    alternateTags,
+                    alternateScript,
+                    sizeof(alternateScript),
+                    err);
+
+            if (U_FAILURE(*err) ||
+                alternateScriptLength >= ULOC_SCRIPT_CAPACITY) {
+                goto error;
+            }
+            else if (alternateScriptLength > 0) {
+                appendTag(
+                    alternateScript,
+                    alternateScriptLength,
+                    tagBuffer,
+                    &tagLength);
+            }
+        }
+
+        if (regionLength > 0) {
+            appendTag(
+                region,
+                regionLength,
+                tagBuffer,
+                &tagLength);
+
+            regionAppended = TRUE;
+        }
+        else if (alternateTags != NULL) {
+            /*
+             * Parse the alternateTags string for the region.
+             */
+            char alternateRegion[ULOC_COUNTRY_CAPACITY];
+
+            const int32_t alternateRegionLength =
+                uloc_getCountry(
+                    alternateTags,
+                    alternateRegion,
+                    sizeof(alternateRegion),
+                    err);
+            if (U_FAILURE(*err) ||
+                alternateRegionLength >= ULOC_COUNTRY_CAPACITY) {
+                goto error;
+            }
+            else if (alternateRegionLength > 0) {
+                appendTag(
+                    alternateRegion,
+                    alternateRegionLength,
+                    tagBuffer,
+                    &tagLength);
+
+                regionAppended = TRUE;
+            }
+        }
+
+        {
+            const int32_t toCopy =
+                tagLength >= tagCapacity ? tagCapacity : tagLength;
+
+            /**
+             * Copy the partial tag from our internal buffer to the supplied
+             * target.
+             **/
+            uprv_memcpy(
+                tag,
+                tagBuffer,
+                toCopy);
+
+            capacityRemaining -= toCopy;
+        }
+
+        if (trailingLength > 0) {
+            if (capacityRemaining > 0 && !regionAppended) {
+                tag[tagLength++] = '_';
+                --capacityRemaining;
+            }
+
+            if (capacityRemaining > 0) {
+                /*
+                 * Copy the trailing data into the supplied buffer.  Use uprv_memmove, since we
+                 * don't know if the user-supplied buffers overlap.
+                 */
+                const int32_t toCopy =
+                    trailingLength >= capacityRemaining ? capacityRemaining : trailingLength;
+
+                uprv_memmove(
+                    &tag[tagLength],
+                    trailing,
+                    toCopy);
+            }
+        }
+
+        tagLength += trailingLength;
+
+        return u_terminateChars(
+                    tag,
+                    tagCapacity,
+                    tagLength,
+                    err);
+    }
+
+error:
+
+    /**
+     * An overflow indicates the locale ID passed in
+     * is ill-formed.  If we got here, and there was
+     * no previous error, it's an implicit overflow.
+     **/
+    if (*err ==  U_BUFFER_OVERFLOW_ERROR ||
+        U_SUCCESS(*err)) {
+        *err = U_ILLEGAL_ARGUMENT_ERROR;
+    }
+
+    return -1;
+}
+
+/**
+ * Create a tag string from the supplied parameters.  The lang, script and region
+ * parameters may be NULL pointers. If they are, their corresponding length parameters
+ * must be less than or equal to 0.  If the lang parameter is an empty string, the
+ * default value for an unknown language is written to the output buffer.
+ *
+ * If the length of the new string exceeds the capacity of the output buffer, 
+ * the function copies as many bytes to the output buffer as it can, and returns
+ * the error U_BUFFER_OVERFLOW_ERROR.
+ *
+ * If an illegal argument is provided, the function returns the error
+ * U_ILLEGAL_ARGUMENT_ERROR.
+ *
+ * @param lang The language tag to use.
+ * @param langLength The length of the language tag.
+ * @param script The script tag to use.
+ * @param scriptLength The length of the script tag.
+ * @param region The region tag to use.
+ * @param regionLength The length of the region tag.
+ * @param trailing Any trailing data to append to the new tag.
+ * @param trailingLength The length of the trailing data.
+ * @param tag The output buffer.
+ * @param tagCapacity The capacity of the output buffer.
+ * @param err A pointer to a UErrorCode for error reporting.
+ * @return The length of the tag string, which may be greater than tagCapacity.
+ **/
+static int32_t U_CALLCONV
+createTagString(
+    const char* lang,
+    int32_t langLength,
+    const char* script,
+    int32_t scriptLength,
+    const char* region,
+    int32_t regionLength,
+    const char* trailing,
+    int32_t trailingLength,
+    char* tag,
+    int32_t tagCapacity,
+    UErrorCode* err)
+{
+    return createTagStringWithAlternates(
+                lang,
+                langLength,
+                script,
+                scriptLength,
+                region,
+                regionLength,
+                trailing,
+                trailingLength,
+                NULL,
+                tag,
+                tagCapacity,
+                err);
+}
+
+/**
+ * Parse the language, script, and region subtags from a tag string, and copy the
+ * results into the corresponding output parameters. The buffers are null-terminated,
+ * unless overflow occurs.
+ *
+ * The langLength, scriptLength, and regionLength parameters are input/output
+ * parameters, and must contain the capacity of their corresponding buffers on
+ * input.  On output, they will contain the actual length of the buffers, not
+ * including the null terminator.
+ *
+ * If the length of any of the output subtags exceeds the capacity of the corresponding
+ * buffer, the function copies as many bytes to the output buffer as it can, and returns
+ * the error U_BUFFER_OVERFLOW_ERROR.  It will not parse any more subtags once overflow
+ * occurs.
+ *
+ * If an illegal argument is provided, the function returns the error
+ * U_ILLEGAL_ARGUMENT_ERROR.
+ *
+ * @param localeID The locale ID to parse.
+ * @param lang The language tag buffer.
+ * @param langLength The length of the language tag.
+ * @param script The script tag buffer.
+ * @param scriptLength The length of the script tag.
+ * @param region The region tag buffer.
+ * @param regionLength The length of the region tag.
+ * @param err A pointer to a UErrorCode for error reporting.
+ * @return The number of chars of the localeID parameter consumed.
+ **/
+static int32_t U_CALLCONV
+parseTagString(
+    const char* localeID,
+    char* lang,
+    int32_t* langLength,
+    char* script,
+    int32_t* scriptLength,
+    char* region,
+    int32_t* regionLength,
+    UErrorCode* err)
+{
+    const char* position = localeID;
+    int32_t subtagLength = 0;
+
+    if(U_FAILURE(*err) ||
+       localeID == NULL ||
+       lang == NULL ||
+       langLength == NULL ||
+       script == NULL ||
+       scriptLength == NULL ||
+       region == NULL ||
+       regionLength == NULL) {
+        goto error;
+    }
+
+    subtagLength = ulocimp_getLanguage(position, lang, *langLength, &position);
+    u_terminateChars(lang, *langLength, subtagLength, err);
+
+    /*
+     * Note that we explicit consider U_STRING_NOT_TERMINATED_WARNING
+     * to be an error, because it indicates the user-supplied tag is
+     * not well-formed.
+     */
+    if(U_FAILURE(*err)) {
+        goto error;
+    }
+
+    *langLength = subtagLength;
+
+    /*
+     * If no language was present, use the value of unknownLanguage
+     * instead.  Otherwise, move past any separator.
+     */
+    if (*langLength == 0) {
+        uprv_strcpy(
+            lang,
+            unknownLanguage);
+        *langLength = (int32_t)uprv_strlen(lang);
+    }
+    else if (_isIDSeparator(*position)) {
+        ++position;
+    }
+
+    subtagLength = ulocimp_getScript(position, script, *scriptLength, &position);
+    u_terminateChars(script, *scriptLength, subtagLength, err);
+
+    if(U_FAILURE(*err)) {
+        goto error;
+    }
+
+    *scriptLength = subtagLength;
+
+    if (*scriptLength > 0) {
+        if (uprv_strnicmp(script, unknownScript, *scriptLength) == 0) {
+            /**
+             * If the script part is the "unknown" script, then don't return it.
+             **/
+            *scriptLength = 0;
+        }
+
+        /*
+         * Move past any separator.
+         */
+        if (_isIDSeparator(*position)) {
+            ++position;
+        }    
+    }
+
+    subtagLength = ulocimp_getCountry(position, region, *regionLength, &position);
+    u_terminateChars(region, *regionLength, subtagLength, err);
+
+    if(U_FAILURE(*err)) {
+        goto error;
+    }
+
+    *regionLength = subtagLength;
+
+    if (*regionLength > 0) {
+        if (uprv_strnicmp(region, unknownRegion, *regionLength) == 0) {
+            /**
+             * If the region part is the "unknown" region, then don't return it.
+             **/
+            *regionLength = 0;
+        }
+    }
+
+exit:
+
+    return (int32_t)(position - localeID);
+
+error:
+
+    /**
+     * If we get here, we have no explicit error, it's the result of an
+     * illegal argument.
+     **/
+    if (!U_FAILURE(*err)) {
+        *err = U_ILLEGAL_ARGUMENT_ERROR;
+    }
+
+    goto exit;
+}
+
+static int32_t U_CALLCONV
+createLikelySubtagsString(
+    const char* lang,
+    int32_t langLength,
+    const char* script,
+    int32_t scriptLength,
+    const char* region,
+    int32_t regionLength,
+    const char* variants,
+    int32_t variantsLength,
+    char* tag,
+    int32_t tagCapacity,
+    UErrorCode* err)
+{
+    /**
+     * ULOC_FULLNAME_CAPACITY will provide enough capacity
+     * that we can build a string that contains the language,
+     * script and region code without worrying about overrunning
+     * the user-supplied buffer.
+     **/
+    char tagBuffer[ULOC_FULLNAME_CAPACITY];
+    char likelySubtagsBuffer[ULOC_FULLNAME_CAPACITY];
+    int32_t tagBufferLength = 0;
+
+    if(U_FAILURE(*err)) {
+        goto error;
+    }
+
+    /**
+     * Try the language with the script and region first.
+     **/
+    if (scriptLength > 0 && regionLength > 0) {
+
+        const char* likelySubtags = NULL;
+
+        tagBufferLength = createTagString(
+            lang,
+            langLength,
+            script,
+            scriptLength,
+            region,
+            regionLength,
+            NULL,
+            0,
+            tagBuffer,
+            sizeof(tagBuffer),
+            err);
+        if(U_FAILURE(*err)) {
+            goto error;
+        }
+
+        likelySubtags =
+            findLikelySubtags(
+                tagBuffer,
+                likelySubtagsBuffer,
+                sizeof(likelySubtagsBuffer),
+                err);
+        if(U_FAILURE(*err)) {
+            goto error;
+        }
+
+        if (likelySubtags != NULL) {
+            /* Always use the language tag from the
+               maximal string, since it may be more
+               specific than the one provided. */
+            return createTagStringWithAlternates(
+                        NULL,
+                        0,
+                        NULL,
+                        0,
+                        NULL,
+                        0,
+                        variants,
+                        variantsLength,
+                        likelySubtags,
+                        tag,
+                        tagCapacity,
+                        err);
+        }
+    }
+
+    /**
+     * Try the language with just the script.
+     **/
+    if (scriptLength > 0) {
+
+        const char* likelySubtags = NULL;
+
+        tagBufferLength = createTagString(
+            lang,
+            langLength,
+            script,
+            scriptLength,
+            NULL,
+            0,
+            NULL,
+            0,
+            tagBuffer,
+            sizeof(tagBuffer),
+            err);
+        if(U_FAILURE(*err)) {
+            goto error;
+        }
+
+        likelySubtags =
+            findLikelySubtags(
+                tagBuffer,
+                likelySubtagsBuffer,
+                sizeof(likelySubtagsBuffer),
+                err);
+        if(U_FAILURE(*err)) {
+            goto error;
+        }
+
+        if (likelySubtags != NULL) {
+            /* Always use the language tag from the
+               maximal string, since it may be more
+               specific than the one provided. */
+            return createTagStringWithAlternates(
+                        NULL,
+                        0,
+                        NULL,
+                        0,
+                        region,
+                        regionLength,
+                        variants,
+                        variantsLength,
+                        likelySubtags,
+                        tag,
+                        tagCapacity,
+                        err);
+        }
+    }
+
+    /**
+     * Try the language with just the region.
+     **/
+    if (regionLength > 0) {
+
+        const char* likelySubtags = NULL;
+
+        createTagString(
+            lang,
+            langLength,
+            NULL,
+            0,
+            region,
+            regionLength,
+            NULL,
+            0,
+            tagBuffer,
+            sizeof(tagBuffer),
+            err);
+        if(U_FAILURE(*err)) {
+            goto error;
+        }
+
+        likelySubtags =
+            findLikelySubtags(
+                tagBuffer,
+                likelySubtagsBuffer,
+                sizeof(likelySubtagsBuffer),
+                err);
+        if(U_FAILURE(*err)) {
+            goto error;
+        }
+
+        if (likelySubtags != NULL) {
+            /* Always use the language tag from the
+               maximal string, since it may be more
+               specific than the one provided. */
+            return createTagStringWithAlternates(
+                        NULL,
+                        0,
+                        script,
+                        scriptLength,
+                        NULL,
+                        0,
+                        variants,
+                        variantsLength,
+                        likelySubtags,
+                        tag,
+                        tagCapacity,
+                        err);
+        }
+    }
+
+    /**
+     * Finally, try just the language.
+     **/
+    {
+        const char* likelySubtags = NULL;
+
+        createTagString(
+            lang,
+            langLength,
+            NULL,
+            0,
+            NULL,
+            0,
+            NULL,
+            0,
+            tagBuffer,
+            sizeof(tagBuffer),
+            err);
+        if(U_FAILURE(*err)) {
+            goto error;
+        }
+
+        likelySubtags =
+            findLikelySubtags(
+                tagBuffer,
+                likelySubtagsBuffer,
+                sizeof(likelySubtagsBuffer),
+                err);
+        if(U_FAILURE(*err)) {
+            goto error;
+        }
+
+        if (likelySubtags != NULL) {
+            /* Always use the language tag from the
+               maximal string, since it may be more
+               specific than the one provided. */
+            return createTagStringWithAlternates(
+                        NULL,
+                        0,
+                        script,
+                        scriptLength,
+                        region,
+                        regionLength,
+                        variants,
+                        variantsLength,
+                        likelySubtags,
+                        tag,
+                        tagCapacity,
+                        err);
+        }
+    }
+
+    return u_terminateChars(
+                tag,
+                tagCapacity,
+                0,
+                err);
+
+error:
+
+    if (!U_FAILURE(*err)) {
+        *err = U_ILLEGAL_ARGUMENT_ERROR;
+    }
+
+    return -1;
+}
+
+#define CHECK_TRAILING_VARIANT_SIZE(trailing, trailingLength) \
+    {   int32_t count = 0; \
+        int32_t i; \
+        for (i = 0; i < trailingLength; i++) { \
+            if (trailing[i] == '-' || trailing[i] == '_') { \
+                count = 0; \
+                if (count > 8) { \
+                    goto error; \
+                } \
+            } else if (trailing[i] == '@') { \
+                break; \
+            } else if (count > 8) { \
+                goto error; \
+            } else { \
+                count++; \
+            } \
+        } \
+    }
+
+static int32_t
+_uloc_addLikelySubtags(const char*    localeID,
+         char* maximizedLocaleID,
+         int32_t maximizedLocaleIDCapacity,
+         UErrorCode* err)
+{
+    char lang[ULOC_LANG_CAPACITY];
+    int32_t langLength = sizeof(lang);
+    char script[ULOC_SCRIPT_CAPACITY];
+    int32_t scriptLength = sizeof(script);
+    char region[ULOC_COUNTRY_CAPACITY];
+    int32_t regionLength = sizeof(region);
+    const char* trailing = "";
+    int32_t trailingLength = 0;
+    int32_t trailingIndex = 0;
+    int32_t resultLength = 0;
+
+    if(U_FAILURE(*err)) {
+        goto error;
+    }
+    else if (localeID == NULL ||
+             maximizedLocaleID == NULL ||
+             maximizedLocaleIDCapacity <= 0) {
+        goto error;
+    }
+
+    trailingIndex = parseTagString(
+        localeID,
+        lang,
+        &langLength,
+        script,
+        &scriptLength,
+        region,
+        &regionLength,
+        err);
+    if(U_FAILURE(*err)) {
+        /* Overflow indicates an illegal argument error */
+        if (*err == U_BUFFER_OVERFLOW_ERROR) {
+            *err = U_ILLEGAL_ARGUMENT_ERROR;
+        }
+
+        goto error;
+    }
+
+    /* Find the length of the trailing portion. */
+    trailing = &localeID[trailingIndex];
+    trailingLength = (int32_t)uprv_strlen(trailing);
+
+    CHECK_TRAILING_VARIANT_SIZE(trailing, trailingLength);
+
+    resultLength =
+        createLikelySubtagsString(
+            lang,
+            langLength,
+            script,
+            scriptLength,
+            region,
+            regionLength,
+            trailing,
+            trailingLength,
+            maximizedLocaleID,
+            maximizedLocaleIDCapacity,
+            err);
+
+    if (resultLength == 0) {
+        const int32_t localIDLength = (int32_t)uprv_strlen(localeID);
+
+        /*
+         * If we get here, we need to return localeID.
+         */
+        uprv_memcpy(
+            maximizedLocaleID,
+            localeID,
+            localIDLength <= maximizedLocaleIDCapacity ? 
+                localIDLength : maximizedLocaleIDCapacity);
+
+        resultLength =
+            u_terminateChars(
+                maximizedLocaleID,
+                maximizedLocaleIDCapacity,
+                localIDLength,
+                err);
+    }
+
+    return resultLength;
+
+error:
+
+    if (!U_FAILURE(*err)) {
+        *err = U_ILLEGAL_ARGUMENT_ERROR;
+    }
+
+    return -1;
+}
+
+static int32_t
+_uloc_minimizeSubtags(const char*    localeID,
+         char* minimizedLocaleID,
+         int32_t minimizedLocaleIDCapacity,
+         UErrorCode* err)
+{
+    /**
+     * ULOC_FULLNAME_CAPACITY will provide enough capacity
+     * that we can build a string that contains the language,
+     * script and region code without worrying about overrunning
+     * the user-supplied buffer.
+     **/
+    char maximizedTagBuffer[ULOC_FULLNAME_CAPACITY];
+    int32_t maximizedTagBufferLength = sizeof(maximizedTagBuffer);
+
+    char lang[ULOC_LANG_CAPACITY];
+    int32_t langLength = sizeof(lang);
+    char script[ULOC_SCRIPT_CAPACITY];
+    int32_t scriptLength = sizeof(script);
+    char region[ULOC_COUNTRY_CAPACITY];
+    int32_t regionLength = sizeof(region);
+    const char* trailing = "";
+    int32_t trailingLength = 0;
+    int32_t trailingIndex = 0;
+
+    if(U_FAILURE(*err)) {
+        goto error;
+    }
+    else if (localeID == NULL ||
+             minimizedLocaleID == NULL ||
+             minimizedLocaleIDCapacity <= 0) {
+        goto error;
+    }
+
+    trailingIndex =
+        parseTagString(
+            localeID,
+            lang,
+            &langLength,
+            script,
+            &scriptLength,
+            region,
+            &regionLength,
+            err);
+    if(U_FAILURE(*err)) {
+
+        /* Overflow indicates an illegal argument error */
+        if (*err == U_BUFFER_OVERFLOW_ERROR) {
+            *err = U_ILLEGAL_ARGUMENT_ERROR;
+        }
+
+        goto error;
+    }
+
+    /* Find the spot where the variants begin, if any. */
+    trailing = &localeID[trailingIndex];
+    trailingLength = (int32_t)uprv_strlen(trailing);
+
+    CHECK_TRAILING_VARIANT_SIZE(trailing, trailingLength);
+
+    createTagString(
+        lang,
+        langLength,
+        script,
+        scriptLength,
+        region,
+        regionLength,
+        NULL,
+        0,
+        maximizedTagBuffer,
+        maximizedTagBufferLength,
+        err);
+    if(U_FAILURE(*err)) {
+        goto error;
+    }
+
+    /**
+     * First, we need to first get the maximization
+     * from AddLikelySubtags.
+     **/
+    maximizedTagBufferLength =
+        uloc_addLikelySubtags(
+            maximizedTagBuffer,
+            maximizedTagBuffer,
+            maximizedTagBufferLength,
+            err);
+
+    if(U_FAILURE(*err)) {
+        goto error;
+    }
+
+    /**
+     * Start first with just the language.
+     **/
+    {
+        char tagBuffer[ULOC_FULLNAME_CAPACITY];
+
+        const int32_t tagBufferLength =
+            createLikelySubtagsString(
+                lang,
+                langLength,
+                NULL,
+                0,
+                NULL,
+                0,
+                NULL,
+                0,
+                tagBuffer,
+                sizeof(tagBuffer),
+                err);
+
+        if(U_FAILURE(*err)) {
+            goto error;
+        }
+        else if (uprv_strnicmp(
+                    maximizedTagBuffer,
+                    tagBuffer,
+                    tagBufferLength) == 0) {
+
+            return createTagString(
+                        lang,
+                        langLength,
+                        NULL,
+                        0,
+                        NULL,
+                        0,
+                        trailing,
+                        trailingLength,
+                        minimizedLocaleID,
+                        minimizedLocaleIDCapacity,
+                        err);
+        }
+    }
+
+    /**
+     * Next, try the language and region.
+     **/
+    if (regionLength > 0) {
+
+        char tagBuffer[ULOC_FULLNAME_CAPACITY];
+
+        const int32_t tagBufferLength =
+            createLikelySubtagsString(
+                lang,
+                langLength,
+                NULL,
+                0,
+                region,
+                regionLength,
+                NULL,
+                0,
+                tagBuffer,
+                sizeof(tagBuffer),
+                err);
+
+        if(U_FAILURE(*err)) {
+            goto error;
+        }
+        else if (uprv_strnicmp(
+                    maximizedTagBuffer,
+                    tagBuffer,
+                    tagBufferLength) == 0) {
+
+            return createTagString(
+                        lang,
+                        langLength,
+                        NULL,
+                        0,
+                        region,
+                        regionLength,
+                        trailing,
+                        trailingLength,
+                        minimizedLocaleID,
+                        minimizedLocaleIDCapacity,
+                        err);
+        }
+    }
+
+    /**
+     * Finally, try the language and script.  This is our last chance,
+     * since trying with all three subtags would only yield the
+     * maximal version that we already have.
+     **/
+    if (scriptLength > 0 && regionLength > 0) {
+        char tagBuffer[ULOC_FULLNAME_CAPACITY];
+
+        const int32_t tagBufferLength =
+            createLikelySubtagsString(
+                lang,
+                langLength,
+                script,
+                scriptLength,
+                NULL,
+                0,
+                NULL,
+                0,
+                tagBuffer,
+                sizeof(tagBuffer),
+                err);
+
+        if(U_FAILURE(*err)) {
+            goto error;
+        }
+        else if (uprv_strnicmp(
+                    maximizedTagBuffer,
+                    tagBuffer,
+                    tagBufferLength) == 0) {
+
+            return createTagString(
+                        lang,
+                        langLength,
+                        script,
+                        scriptLength,
+                        NULL,
+                        0,
+                        trailing,
+                        trailingLength,
+                        minimizedLocaleID,
+                        minimizedLocaleIDCapacity,
+                        err);
+        }
+    }
+
+    {
+        /**
+         * If we got here, return the locale ID parameter.
+         **/
+        const int32_t localeIDLength = (int32_t)uprv_strlen(localeID);
+
+        uprv_memcpy(
+            minimizedLocaleID,
+            localeID,
+            localeIDLength <= minimizedLocaleIDCapacity ? 
+                localeIDLength : minimizedLocaleIDCapacity);
+
+        return u_terminateChars(
+                    minimizedLocaleID,
+                    minimizedLocaleIDCapacity,
+                    localeIDLength,
+                    err);
+    }
+
+error:
+
+    if (!U_FAILURE(*err)) {
+        *err = U_ILLEGAL_ARGUMENT_ERROR;
+    }
+
+    return -1;
+
+
+}
+
+static UBool
+do_canonicalize(const char*    localeID,
+         char* buffer,
+         int32_t bufferCapacity,
+         UErrorCode* err)
+{
+    uloc_canonicalize(
+        localeID,
+        buffer,
+        bufferCapacity,
+        err);
+
+    if (*err == U_STRING_NOT_TERMINATED_WARNING ||
+        *err == U_BUFFER_OVERFLOW_ERROR) {
+        *err = U_ILLEGAL_ARGUMENT_ERROR;
+
+        return FALSE;
+    }
+    else if (U_FAILURE(*err)) {
+
+        return FALSE;
+    }
+    else {
+        return TRUE;
+    }
+}
+
+U_DRAFT int32_t U_EXPORT2
+uloc_addLikelySubtags(const char*    localeID,
+         char* maximizedLocaleID,
+         int32_t maximizedLocaleIDCapacity,
+         UErrorCode* err)
+{
+    char localeBuffer[ULOC_FULLNAME_CAPACITY];
+
+    if (!do_canonicalize(
+        localeID,
+        localeBuffer,
+        sizeof(localeBuffer),
+        err)) {
+        return -1;
+    }
+    else {
+        return _uloc_addLikelySubtags(
+                    localeBuffer,
+                    maximizedLocaleID,
+                    maximizedLocaleIDCapacity,
+                    err);
+    }    
+}
+
+U_DRAFT int32_t U_EXPORT2
+uloc_minimizeSubtags(const char*    localeID,
+         char* minimizedLocaleID,
+         int32_t minimizedLocaleIDCapacity,
+         UErrorCode* err)
+{
+    char localeBuffer[ULOC_FULLNAME_CAPACITY];
+
+    if (!do_canonicalize(
+        localeID,
+        localeBuffer,
+        sizeof(localeBuffer),
+        err)) {
+        return -1;
+    }
+    else {
+        return _uloc_minimizeSubtags(
+                    localeBuffer,
+                    minimizedLocaleID,
+                    minimizedLocaleIDCapacity,
+                    err);
+    }    
+}