From d2bab1788df2f6bf184574f94195d23111ed9d6b Mon Sep 17 00:00:00 2001 From: scf Date: Sun, 3 Aug 2008 22:47:23 +0000 Subject: Restructure and use different variables in the tests that involve environ[0] to be more obvious that environ is not NULL before environ[0] is tested. Although I believe the previous code worked, this change improves code maintainability. Reviewed by: ache MFC after: 3 days --- lib/libc/stdlib/getenv.c | 28 +++++++++++++++------------- 1 file changed, 15 insertions(+), 13 deletions(-) (limited to 'lib/libc/stdlib') diff --git a/lib/libc/stdlib/getenv.c b/lib/libc/stdlib/getenv.c index 0f84082..2abf7fc 100644 --- a/lib/libc/stdlib/getenv.c +++ b/lib/libc/stdlib/getenv.c @@ -190,10 +190,6 @@ __findenv_environ(const char *name, size_t nameLen) { int envNdx; - /* Check for non-existant environment. */ - if (environ == NULL) - return (NULL); - /* Find variable within environ. */ for (envNdx = 0; environ[envNdx] != NULL; envNdx++) if (strncmpeq(environ[envNdx], name, nameLen)) @@ -430,14 +426,18 @@ getenv(const char *name) } /* - * Find environment variable via environ if no changes have been made - * via a *env() call or environ has been replaced or cleared by a - * running program, otherwise, use the rebuilt environment. + * An empty environment (environ or its first value) regardless if + * environ has been copied before will return a NULL. + * + * If the environment is not empty, find an environment variable via + * environ if environ has not been copied via an *env() call or been + * replaced by a running program, otherwise, use the rebuilt + * environment. */ - if (envVars == NULL || environ != intEnviron) - return (__findenv_environ(name, nameLen)); - else if (environ[0] == NULL) + if (environ == NULL || environ[0] == NULL) return (NULL); + else if (envVars == NULL || environ != intEnviron) + return (__findenv_environ(name, nameLen)); else { envNdx = envVarsTotal - 1; return (__findenv(name, nameLen, &envNdx, true)); @@ -537,10 +537,12 @@ __merge_environ(void) char *equals; /* - * Internally-built environ has been replaced or cleared. clean up - * everything. + * Internally-built environ has been replaced or cleared (detected by + * using the count of active variables against a NULL as the first value + * in environ). Clean up everything. */ - if (envVarsTotal > 0 && (environ != intEnviron || environ[0] == NULL)) { + if (intEnviron != NULL && (environ != intEnviron || (envActive > 0 && + environ[0] == NULL))) { /* Deactivate all environment variables. */ if (envActive > 0) { origEnviron = NULL; -- cgit v1.1