From: Johannes Sixt Date: Mon, 06 Jun 2011 07:08:13 GMT Subject: [PATCH 3/3] Windows: teach getenv to do a case-sensitive search Message-ID: <4DEC7CDD.10403@viscovery.net> In-Reply-To: <4DEC7A65.7020207@viscovery.net> From: Johannes Sixt getenv() on Windows looks up environment variables in a case-insensitive manner. Even though all documentations claim that the environment is case-insensitive, it is possible for applications to pass an environment to child processes that has variables that differ only in case. Bash on Windows does this, for example, and sh-i18n--envsubst depends on this behavior. With this patch environment variables are first looked up in a case-sensitive manner; only if this finds nothing, the system's getenv() is used as a fallback. Signed-off-by: Johannes Sixt --- compat/mingw.c | 23 ++++++++++++++++++++--- 1 files changed, 20 insertions(+), 3 deletions(-) diff --git a/compat/mingw.c b/compat/mingw.c index ee480f9..6e5af32 100644 --- a/compat/mingw.c +++ b/compat/mingw.c @@ -1116,14 +1116,31 @@ char **make_augmented_environ(const char *const *vars) } #undef getenv + +/* + * The system's getenv looks up the name in a case-insensitive manner. + * This version tries a case-sensitive lookup and falls back to + * case-insensitive if nothing was found. This is necessary because, + * as a prominent example, CMD sets 'Path', but not 'PATH'. + * Warning: not thread-safe. + */ +static char *getenv_cs(const char *name) +{ + size_t len = strlen(name); + int i = lookup_env(environ, name, len); + if (i >= 0) + return environ[i] + len + 1; /* skip past name and '=' */ + return getenv(name); +} + char *mingw_getenv(const char *name) { - char *result = getenv(name); + char *result = getenv_cs(name); if (!result && !strcmp(name, "TMPDIR")) { /* on Windows it is TMP and TEMP */ - result = getenv("TMP"); + result = getenv_cs("TMP"); if (!result) - result = getenv("TEMP"); + result = getenv_cs("TEMP"); } return result; } -- 1.7.6.rc0.1186.gfb4fd