diff options
| -rw-r--r-- | common/str.cpp | 16 |
1 files changed, 12 insertions, 4 deletions
diff --git a/common/str.cpp b/common/str.cpp index 4585905d62..c3c19adfe6 100644 --- a/common/str.cpp +++ b/common/str.cpp @@ -439,12 +439,20 @@ String String::printf(const char *fmt, ...) { int len = vsnprintf(output._str, _builtinCapacity, fmt, va); va_end(va); - if (len == -1) { - // MSVC doesn't return the size the full string would take up. - // Try increasing the size of the string until it fits. + if (len == -1 || len == _builtinCapacity - 1) { + // MSVC and IRIX don't return the size the full string would take up. + // MSVC returns -1, IRIX returns the number of characters actually written, + // which is at the most the size of the buffer minus one, as the string is + // truncated to fit. // We assume MSVC failed to output the correct, null-terminated string // if the return value is either -1 or size. + // For IRIX, because we lack a better mechanism, we assume failure + // if the return value equals size - 1. + // The downside to this is that whenever we try to format a string where the + // size is 1 below the built-in capacity, the size is needlessly increased. + + // Try increasing the size of the string until it fits. int size = _builtinCapacity; do { size *= 2; @@ -455,7 +463,7 @@ String String::printf(const char *fmt, ...) { va_start(va, fmt); len = vsnprintf(output._str, size, fmt, va); va_end(va); - } while (len == -1 || len >= size); + } while (len == -1 || len >= size - 1); output._size = len; } else if (len < (int)_builtinCapacity) { // vsnprintf succeeded |