commit c8ccd028a78d154c3b82138f7827aec0e2de13dd Author: Nick Mathewson nickm@torproject.org Date: Mon Jul 2 11:50:17 2018 -0400

Don't redefine str(n)casecmp on windows unless they're missing

When we do redefine them, use inline functions instead of #define.

This fixes a latent code problem in our redefinition of these functions, which was exposed by our refactoring: Previously, we would #define strcasecmp after string.h was included, so nothing bad would happen. But when we refactored, we would sometimes #define it first, which was a problem on mingw, whose headers contain (approximately):

inline int strcasecmp (const char *a, const char *b) { return _stricmp(a,b); }

Our define turned this into: inline int _stricmp(const char *a, const char *b) { return _stricmp(a,b); }

And GCC would correctly infer that this function would loop forever, rather than actually comparing anything. This caused bug 26594.

Fixes bug 26594; bug not in any released version of Tor. --- configure.ac | 2 ++ src/lib/string/compat_string.h | 17 ++++++++++++++--- 2 files changed, 16 insertions(+), 3 deletions(-)

diff --git a/configure.ac b/configure.ac index 97e8dadeb..98635bcbd 100644 --- a/configure.ac +++ b/configure.ac @@ -610,6 +610,8 @@ AC_CHECK_FUNCS( sigaction \ socketpair \ statvfs \ + strncasecmp \ + strcasecmp \ strlcat \ strlcpy \ strnlen \ diff --git a/src/lib/string/compat_string.h b/src/lib/string/compat_string.h index 24cd0f8b1..0a4ce0175 100644 --- a/src/lib/string/compat_string.h +++ b/src/lib/string/compat_string.h @@ -13,9 +13,20 @@

/* ===== String compatibility */ #ifdef _WIN32 -/* Windows names string functions differently from most other platforms. */ -#define strncasecmp _strnicmp -#define strcasecmp _stricmp +/* Windows doesn't have str(n)casecmp, but mingw defines it: only define it + * ourselves if it's missing. */ +#ifndef HAVE_STRNCASECMP +static inline int strncasecmp(const char *a, const char *b, size_t n); +static inline int strncasecmp(const char *a, const char *b, size_t n) { + return strncmpi(a,b); +} +#endif +#ifndef HAVE_STRCASECMP +static inline int strcasecmp(const char *a, const char *b, size_t n); +static inline int strcasecmp(const char *a, const char *b, size_t n) { + return strcmpi(a,b); +} +#endif #endif

#if defined __APPLE__