U_BUFFER_OVERFLOW_ERROR

U_BUFFER_OVERFLOW_ERROR

Error message

icupkg/makeTargetName(%s) target item name length %ld too long\n

What it means

makeTargetName composes target = treePart + id + suffix and checks the total against the caller's fixed-size buffer capacity; if targetLength >= capacity it prints the item name + length and sets *pErrorCode = U_BUFFER_OVERFLOW_ERROR (returns, does not exit). The capacity comes from sizeof() a local char[] at the call sites.

Source

Thrown at deps/icu-small/source/tools/toolutil/pkgitems.cpp:152

    int32_t treeLength, suffixLength, targetLength;

    // get the item basename
    itemID=strrchr(itemName, '/');
    if(itemID!=nullptr) {
        ++itemID;
    } else {
        itemID=itemName;
    }

    // build the target string
    treeLength = static_cast<int32_t>(itemID - itemName);
    if(idLength<0) {
        idLength = static_cast<int32_t>(strlen(id));
    }
    suffixLength = static_cast<int32_t>(strlen(suffix));
    targetLength=treeLength+idLength+suffixLength;
    if(targetLength>=capacity) {
        fprintf(stderr, "icupkg/makeTargetName(%s) target item name length %ld too long\n",
                        itemName, static_cast<long>(targetLength));
        *pErrorCode=U_BUFFER_OVERFLOW_ERROR;
        return;
    }

    memcpy(target, itemName, treeLength);
    memcpy(target+treeLength, id, idLength);
    memcpy(target+treeLength+idLength, suffix, suffixLength+1); // +1 includes the terminating NUL
}

static void 
checkIDSuffix(const char *itemName, const char *id, int32_t idLength, const char *suffix,
              CheckDependency check, void *context,
              UErrorCode *pErrorCode) {
    char target[200];
    makeTargetName(itemName, id, idLength, suffix, target, static_cast<int32_t>(sizeof(target)), pErrorCode);
    if(U_SUCCESS(*pErrorCode)) {
        check(context, itemName, target);

View on GitHub (pinned to 1b2de5e052)

Solutions

Shorten the item/locale names in the source data, or restructure the resource tree to be shallower.
Rebuild pkgitems with a larger target buffer at the call sites (sizeof target) if long names are legitimate.
Audit the .dat for items with unexpectedly long names (`icupkg -l`).
Validate name lengths before packaging and reject over-length entries upstream.

Example fix

// before (pkgitems.cpp call site uses a fixed local buffer)
char target[256];
makeTargetName(itemName, id, idLen, ".res", target, (int32_t)sizeof(target), &errorCode);
// after
char target[1024];  // only if legitimately long names are required
makeTargetName(itemName, id, idLen, ".res", target, (int32_t)sizeof(target), &errorCode);

Defensive patterns

Strategy: validation

Validate before calling

// reject items whose composed target name would overflow a reasonable bound
size_t treeLen = strnlen(itemName, 256), idLen = idLength >= 0 ? (size_t)idLength : strlen(id), sufLen = strlen(suffix);
if (treeLen + idLen + sufLen >= capacity) { *pErrorCode = U_BUFFER_OVERFLOW_ERROR; return; }

Try / catch

// caller checks UErrorCode after makeTargetName (it sets the code, does not exit)
UErrorCode err = U_ZERO_ERROR;
makeTargetName(itemName, id, idLen, suffix, target, (int32_t)sizeof(target), &err);
if (U_FAILURE(err)) { /* log and skip this item; do not use target */ }

Prevention

Always check *pErrorCode after makeTargetName — it returns, it does not abort.
Keep resource/locale tree paths shallow and names reasonably short.
If long names are legitimate, enlarge the target buffer at the call site and rebuild.
Audit .dat contents with `icupkg -l` for pathologically named items.

When it happens

Trigger: An item whose name (tree path + id + suffix like .res) exceeds the stack buffer size passed in. The check `if(targetLength>=capacity)` fires before the memcpy block.

Common situations: A locale/resource path with many path components, or an unusually long locale ID, exceeding the fixed target buffer; a .dat containing pathologically named items.

Related errors

AI-assisted analysis of nodejs/node@1b2de5e052 (2026-08-13). Data as JSON: /api/errors/16ff7a2776e56ee5. Report an issue: GitHub.