Index: lib/libc/stdlib/getenv.c
===================================================================
RCS file: /home/ncvs/src/lib/libc/stdlib/getenv.c,v
retrieving revision 1.9
diff -u -r1.9 getenv.c
--- lib/libc/stdlib/getenv.c	4 Jul 2007 00:00:39 -0000	1.9
+++ lib/libc/stdlib/getenv.c	14 Jul 2007 00:59:51 -0000
@@ -36,6 +36,12 @@
 __FBSDID("$FreeBSD: src/lib/libc/stdlib/getenv.c,v 1.9 2007/07/04 00:00:39 scf Exp $");
 
 
+static const char CorruptEnvFindMsg[] =
+    "environment corrupt; unable to find %.*s";
+static const char CorruptEnvValueMsg[] =
+    "environment corrupt; missing value for %s";
+
+
 /*
  * Standard environ.  environ variable is exposed to entire process.
  *
@@ -43,9 +49,11 @@
  *			allows environ to return to as it was before.
  *	environSize:	Number of variables environ can hold.  Can only
  *			increase.
+ *	watchEnviron:	Pointer to watch for changes by program to environ.
  */
 extern char **environ;
 static char **origEnviron;
+static char **watchEnviron = NULL;
 static int environSize = 0;
 
 /*
@@ -84,7 +92,7 @@
 
 
 /* Deinitialization of new environment. */
-static void __attribute__ ((destructor)) __clean_env(void);
+static void __attribute__ ((destructor)) __clean_env_destructor(void);
 
 
 /*
@@ -173,6 +181,64 @@
 
 
 /*
+ * Remove variable added by putenv() from variable tracking array.
+ */
+static void
+__remove_putenv(int envNdx)
+{
+	envVarsTotal--;
+	if (envVarsTotal > envNdx)
+		memmove(&(envVars[envNdx]), &(envVars[envNdx + 1]),
+		    (envVarsTotal - envNdx) * sizeof (*envVars));
+	memset(&(envVars[envVarsTotal]), 0, sizeof (*envVars));
+
+	return;
+}
+
+
+/*
+ * Deallocate the environment built from environ as well as environ then set
+ * both to NULL.  Eases debugging of memory leaks.
+ */
+static void
+__clean_env(bool freeVars)
+{
+	int envNdx;
+
+	/* Deallocate environment and environ if created by *env(). */
+	if (envVars != NULL) {
+		for (envNdx = envVarsTotal - 1; envNdx >= 0; envNdx--)
+			/* Free variables or deactivate them. */
+			if (envVars[envNdx].putenv) {
+				if (!freeVars)
+					__remove_putenv(envNdx);
+			} else {
+				if (freeVars)
+					free(envVars[envNdx].name);
+				else
+					envVars[envNdx].active = false;
+			}
+		if (freeVars) {
+			free(envVars);
+			envVars = NULL;
+		} else
+			envActive = 0;
+
+		/* Restore original environ if it has not updated by program. */
+		if (origEnviron != NULL) {
+			if (watchEnviron == environ)
+				environ = origEnviron;
+			free(watchEnviron);
+			watchEnviron = NULL;
+			environSize = 0;
+		}
+	}
+
+	return;
+}
+
+
+/*
  * Using the environment, rebuild the environ array for use by other C library
  * calls that depend upon it.
  */
@@ -193,6 +259,7 @@
 			return (-1);
 		environSize = tmpEnvironSize;
 		environ = tmpEnviron;
+		watchEnviron = environ;
 	}
 	envActive = newEnvironSize;
 
@@ -246,10 +313,8 @@
 	size_t nameLen;
 
 	/* Check for non-existant environment. */
-	if (environ == NULL)
+	if (environ == NULL || environ[0] == NULL)
 		return (0);
-	if (environ[0] == NULL)
-		goto SaveEnviron;
 
 	/* Count environment variables. */
 	for (env = environ, envVarsTotal = 0; *env != NULL; env++)
@@ -274,8 +339,7 @@
 			envVars[envNdx].valueSize =
 			    strlen(envVars[envNdx].value);
 		} else {
-			warnx("environment corrupt; missing value for %s",
-			    envVars[envNdx].name);
+			warnx(CorruptEnvValueMsg, envVars[envNdx].name);
 			errno = EFAULT;
 			goto Failure;
 		}
@@ -290,8 +354,7 @@
 		activeNdx = envVarsTotal - 1;
 		if (__findenv(envVars[envNdx].name, nameLen, &activeNdx,
 		    false) == NULL) {
-			warnx("environment corrupt; unable to find %.*s",
-			    nameLen, envVars[envNdx].name);
+			warnx(CorruptEnvFindMsg, nameLen, envVars[envNdx].name);
 			errno = EFAULT;
 			goto Failure;
 		}
@@ -299,24 +362,20 @@
 	}
 
 	/* Create a new environ. */
-SaveEnviron:
 	origEnviron = environ;
 	environ = NULL;
-	if (envVarsTotal > 0) {
-		rtrnVal = __rebuild_environ(envVarsTotal);
-		if (rtrnVal == -1) {
-			savedErrno = errno;
-			__clean_env();
-			errno = savedErrno;
-		}
-	} else
-		rtrnVal = 0;
+	rtrnVal = __rebuild_environ(envVarsTotal);
+	if (rtrnVal == -1) {
+		savedErrno = errno;
+		__clean_env(true);
+		errno = savedErrno;
+	}
 
 	return (rtrnVal);
 
 Failure:
 	savedErrno = errno;
-	__clean_env();
+	__clean_env(true);
 	errno = savedErrno;
 
 	return (-1);
@@ -324,42 +383,12 @@
 
 
 /*
- * Remove variable added by putenv() from variable tracking array.
+ * Destructor function with default argument to __clean_env().
  */
 static void
-__remove_putenv(int envNdx)
+__clean_env_destructor(void)
 {
-	memmove(&(envVars[envNdx]), &(envVars[envNdx + 1]),
-	    (envVarsTotal - envNdx) * sizeof (*envVars));
-	envVarsTotal--;
-
-	return;
-}
-
-
-/*
- * Deallocate the environment built from environ as well as environ then set
- * both to NULL.  Eases debugging of memory leaks.
- */
-static void
-__clean_env(void)
-{
-	int envNdx;
-
-	/* Deallocate environment and environ if created by *env(). */
-	if (envVars != NULL) {
-		for (envNdx = 0; envNdx < envVarsTotal; envNdx++)
-			if (!envVars[envNdx].putenv)
-				free(envVars[envNdx].name);
-		free(envVars);
-		envVars = NULL;
-
-		/* Restore original environ. */
-		if (origEnviron != NULL) {
-			free(environ);
-			environ = origEnviron;
-		}
-	}
+	__clean_env(true);
 
 	return;
 }
@@ -380,8 +409,12 @@
 		return (NULL);
 	}
 
-	/* Find environment variable via environ or rebuilt environment. */
-	if (envVars == NULL)
+	/*
+	 * Find environment variable via environ if no changes have been made
+	 * via a *env() call or environ has been replaced by a running program,
+	 * otherwise, use the rebuilt environment.
+	 */
+	if (envVars == NULL || environ != watchEnviron)
 		return (__findenv_environ(name, nameLen));
 	else {
 		envNdx = envVarsTotal - 1;
@@ -395,27 +428,19 @@
  * older setting has enough room to store the new value, it will be reused.  No
  * previous variables are ever freed here to avoid causing a segmentation fault
  * in a user's code.
+ *
+ * The variables nameLen and valueLen are passed into here to allow the caller
+ * to calculate the length by means besides just strlen().
  */
-int
-setenv(const char *name, const char *value, int overwrite)
+static int
+__setenv(const char *name, size_t nameLen, const char *value, int overwrite)
 {
 	bool reuse;
 	char *env;
 	int envNdx;
 	int newEnvActive;
-	size_t nameLen;
 	size_t valueLen;
 
-	/* Check for malformed name. */
-	if (name == NULL || (nameLen = __strleneq(name)) == 0) {
-		errno = EINVAL;
-		return (-1);
-	}
-
-	/* Initialize environment. */
-	if (envVars == NULL && __build_env() == -1)
-		return (-1);
-
 	/* Find existing environment variable large enough to use. */
 	envNdx = envVarsTotal - 1;
 	newEnvActive = envActive;
@@ -437,7 +462,6 @@
 		/* Entry is large enough to reuse. */
 		else if (envVars[envNdx].valueSize >= valueLen)
 			reuse = true;
-
 	}
 
 	/* Create new variable if none was found of sufficient size. */
@@ -480,7 +504,71 @@
 
 
 /*
- * Insert a "name=value" string into then environment.  Special settings must be
+ * If the program attempts to replace the array of environment variables
+ * (environ) environ, then deactivate all variables and merge in the new list
+ * from environ.
+ */
+static int
+__merge_environ(void)
+{
+	char **env;
+	char *equals;
+
+	/* environ has been replaced.  clean up everything. */
+	if (envVarsTotal > 0 && environ != watchEnviron) {
+		/* Deactivate all environment variables. */
+		origEnviron = NULL;
+		__clean_env(false);
+
+		/*
+		 * Insert new environ into existing, yet deactivated,
+		 * environment array.
+		 */
+		origEnviron = environ;
+		environ = watchEnviron;
+		if (origEnviron != NULL)
+			for (env = origEnviron; *env != NULL; env++) {
+				if ((equals = strchr(*env, '=')) == NULL) {
+					warnx(CorruptEnvValueMsg, *env);
+					errno = EFAULT;
+					return (-1);
+				}
+				if (__setenv(*env, equals - *env, equals + 1,
+				    1) == -1)
+					return (-1);
+			}
+	}
+
+	return (0);
+}
+
+
+/*
+ * The exposed setenv() that peforms a few tests before calling the function
+ * (__setenv()) that does the actual work of inserting a variable into the
+ * environment.
+ */
+int
+setenv(const char *name, const char *value, int overwrite)
+{
+	size_t nameLen;
+
+	/* Check for malformed name. */
+	if (name == NULL || (nameLen = __strleneq(name)) == 0) {
+		errno = EINVAL;
+		return (-1);
+	}
+
+	/* Initialize environment. */
+	if (__merge_environ() == -1 || (envVars == NULL && __build_env() == -1))
+		return (-1);
+
+	return (__setenv(name, nameLen, value, overwrite));
+}
+
+
+/*
+ * Insert a "name=value" string into the environment.  Special settings must be
  * made to keep setenv() from reusing this memory block and unsetenv() from
  * allowing it to be tracked.
  */
@@ -500,7 +588,7 @@
 	}
 
 	/* Initialize environment. */
-	if (envVars == NULL && __build_env() == -1)
+	if (__merge_environ() == -1 || (envVars == NULL && __build_env() == -1))
 		return (-1);
 
 	/* Deactivate previous environment variable. */
@@ -552,7 +640,7 @@
 	}
 
 	/* Initialize environment. */
-	if (envVars == NULL && __build_env() == -1)
+	if (__merge_environ() == -1 || (envVars == NULL && __build_env() == -1))
 		return (-1);
 
 	/* Deactivate specified variable. */
cvs diff: Diffing tools/regression/environ
Index: tools/regression/environ/envctl.c
===================================================================
RCS file: /home/ncvs/src/tools/regression/environ/envctl.c,v
retrieving revision 1.1
diff -u -r1.1 envctl.c
--- tools/regression/environ/envctl.c	4 Jul 2007 00:00:39 -0000	1.1
+++ tools/regression/environ/envctl.c	14 Jul 2007 01:00:11 -0000
@@ -54,17 +54,19 @@
 static void
 usage(const char *program)
 {
-	fprintf(stderr, "Usage:  %s [-DGUcht] [-gu name] [-p name=value] "
+	fprintf(stderr, "Usage:  %s [-CDGUchrt] [-gu name] [-p name=value] "
 	    "[(-S|-s name) value overwrite]\n\n"
 	    "Options:\n"
+	    "  -C\t\t\t\tClear environ variable with NULL pointer\n"
 	    "  -D\t\t\t\tDump environ\n"
 	    "  -G name\t\t\tgetenv(NULL)\n"
 	    "  -S value overwrite\t\tsetenv(NULL, value, overwrite)\n"
 	    "  -U\t\t\t\tunsetenv(NULL)\n"
-	    "  -c\t\t\t\tClear environ variable\n"
+	    "  -c\t\t\t\tClear environ variable with calloc()'d memory\n"
 	    "  -g name\t\t\tgetenv(name)\n"
 	    "  -h\t\t\t\tHelp\n"
 	    "  -p name=value\t\t\tputenv(name=value)\n"
+	    "  -r\t\t\t\treplace environ with { \"FOO=bar\", NULL }\n"
 	    "  -s name value overwrite\tsetenv(name, value, overwrite)\n"
 	    "  -t\t\t\t\tOutput is suitable for testing (no newlines)\n"
 	    "  -u name\t\t\tunsetenv(name)\n",
@@ -77,7 +79,7 @@
 int
 main(int argc, char **argv)
 {
-	char *cleanEnv[] = { NULL };
+	char *staticEnv[] = { "FOO=bar", NULL };
 	char arg;
 	const char *eol = "\n";
 	const char *value;
@@ -87,15 +89,19 @@
 		exit(EXIT_FAILURE);
 	}
 
-	while ((arg = getopt(argc, argv, "DGS:Ucg:hp:s:tu:")) != -1) {
+	while ((arg = getopt(argc, argv, "DGS:Ucg:hp:rs:tu:")) != -1) {
 		switch (arg) {
-			case 'D':
-				errno = 0;
-				dump_environ();
+			case 'C':
+				environ = NULL;
 				break;
 
 			case 'c':
-				environ = cleanEnv;
+				environ = calloc(1, sizeof(*environ));
+				break;
+
+			case 'D':
+				errno = 0;
+				dump_environ();
 				break;
 
 			case 'G':
@@ -113,6 +119,10 @@
 				printf("%d %d%s", putenv(optarg), errno, eol);
 				break;
 
+			case 'r':
+				environ = staticEnv;
+				break;
+
 			case 'S':
 				errno = 0;
 				printf("%d %d%s", setenv(NULL, optarg,
Index: tools/regression/environ/envtest.t
===================================================================
RCS file: /home/ncvs/src/tools/regression/environ/envtest.t,v
retrieving revision 1.1
diff -u -r1.1 envtest.t
--- tools/regression/environ/envtest.t	4 Jul 2007 00:00:39 -0000	1.1
+++ tools/regression/environ/envtest.t	14 Jul 2007 01:00:11 -0000
@@ -132,6 +132,9 @@
 	-g FOO
 check_result "0 0 0 0 0 0 0 0 ${BAR}"
 
+run_test -c -s FOO ${BAR} 1 -g FOO -c -s FOO ${NEWBAR} 1 -g FOO
+check_result "0 0 ${BAR} 0 0 ${NEWBAR}"
+
 
 # Unsets.
 run_test -u FOO -g FOO
@@ -152,6 +155,10 @@
 run_test -c -s FOO ${NEWBAR} 1 -g FOO -u FOO -g FOO
 check_result "0 0 ${NEWBAR} 0 0"
 
+run_test -c -u FOO -s FOO ${BAR} 1 -g FOO -u FOO -g FOO -c -u FOO\
+	-s FOO ${NEWBAR} 1 -g FOO
+check_result "0 0 0 0 ${BAR} 0 0  0 0 0 0 ${NEWBAR}"
+
 
 # Puts.
 run_test -p FOO=${NEWBAR} -g FOO
@@ -180,3 +187,17 @@
 
 run_test -s FOO ${NEWBAR} 1 -p FOO=${BAR} -u FOO
 check_result "0 0 0 0 0 0"
+
+run_test -s FOO ${NEWBAR} 1 -p FOO=${BAR} -c -g FOO -p FOO=${NEWBAR} -g FOO
+check_result "0 0 0 0  0 0 ${NEWBAR}"
+
+run_test -c -p FOO=${BAR} -g FOO -c -p FOO=${NEWBAR} -g FOO
+check_result "0 0 ${BAR} 0 0 ${NEWBAR}"
+
+
+# environ replacements.
+run_test -r -g FOO -s FOO ${BAR} 1 -g FOO -u FOO -g FOO
+check_result "${BAR} 0 0 ${BAR} 0 0"
+
+run_test -r -g FOO -u FOO -g FOO -s FOO ${BAR} 1 -g FOO
+check_result "${BAR} 0 0  0 0 ${BAR}"
Index: tools/regression/environ/timings.c
===================================================================
RCS file: /home/ncvs/src/tools/regression/environ/timings.c,v
retrieving revision 1.1
diff -u -r1.1 timings.c
--- tools/regression/environ/timings.c	4 Jul 2007 00:00:39 -0000	1.1
+++ tools/regression/environ/timings.c	14 Jul 2007 01:00:11 -0000
@@ -23,7 +23,9 @@
  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  * SUCH DAMAGE.
  */
+#include <sys/types.h>
 #include <sys/time.h>
+#include <sys/resource.h>
 #include <err.h>
 #include <stdio.h>
 #include <stdlib.h>
@@ -64,43 +66,44 @@
 main(int argc, char **argv)
 {
 	int iterations;
-	struct timeval endTime;
-	struct timeval startTime;
+	struct rusage endUsage;
+	struct rusage startUsage;
 
 	/*
 	 * getenv() on the existing environment.
 	 */
-	gettimeofday(&startTime, NULL);
+	getrusage(RUSAGE_SELF, &startUsage);
 
 	/* Iterate over setting variable. */
 	for (iterations = 0; iterations < MaxIterations; iterations++)
 		if (getenv(name) == NULL)
 			err(EXIT_FAILURE, "getenv(name)");
 
-	gettimeofday(&endTime, NULL);
+	getrusage(RUSAGE_SELF, &endUsage);
 
-	report_time("getenv(name)", &startTime, &endTime);
+	report_time("getenv(name)", &startUsage.ru_utime, &endUsage.ru_utime);
 
 
 	/*
 	 * setenv() a variable with a large value.
 	 */
-	gettimeofday(&startTime, NULL);
+	getrusage(RUSAGE_SELF, &startUsage);
 
 	/* Iterate over setting variable. */
 	for (iterations = 0; iterations < MaxIterations; iterations++)
 		if (setenv(name, value1, 1) == -1)
 			err(EXIT_FAILURE, "setenv(name, value1, 1)");
 
-	gettimeofday(&endTime, NULL);
+	getrusage(RUSAGE_SELF, &endUsage);
 
-	report_time("setenv(name, value1, 1)", &startTime, &endTime);
+	report_time("setenv(name, value1, 1)", &startUsage.ru_utime,
+	    &endUsage.ru_utime);
 
 
 	/*
 	 * getenv() the new variable on the new environment.
 	 */
-	gettimeofday(&startTime, NULL);
+	getrusage(RUSAGE_SELF, &startUsage);
 
 	/* Iterate over setting variable. */
 	for (iterations = 0; iterations < MaxIterations; iterations++)
@@ -108,15 +111,15 @@
 		if (getenv(name) == NULL)
 			err(EXIT_FAILURE, "getenv(name)");
 
-	gettimeofday(&endTime, NULL);
+	getrusage(RUSAGE_SELF, &endUsage);
 
-	report_time("getenv(name)", &startTime, &endTime);
+	report_time("getenv(name)", &startUsage.ru_utime, &endUsage.ru_utime);
 
 
 	/*
 	 * getenv() a different variable on the new environment.
 	 */
-	gettimeofday(&startTime, NULL);
+	getrusage(RUSAGE_SELF, &startUsage);
 
 	/* Iterate over setting variable. */
 	for (iterations = 0; iterations < MaxIterations; iterations++)
@@ -124,30 +127,31 @@
 		if (getenv(name2) == NULL)
 			err(EXIT_FAILURE, "getenv(name2)");
 
-	gettimeofday(&endTime, NULL);
+	getrusage(RUSAGE_SELF, &endUsage);
 
-	report_time("getenv(name2)", &startTime, &endTime);
+	report_time("getenv(name2)", &startUsage.ru_utime, &endUsage.ru_utime);
 
 
 	/*
 	 * setenv() a variable with a small value.
 	 */
-	gettimeofday(&startTime, NULL);
+	getrusage(RUSAGE_SELF, &startUsage);
 
 	/* Iterate over setting variable. */
 	for (iterations = 0; iterations < MaxIterations; iterations++)
 		if (setenv(name, value2, 1) == -1)
 			err(EXIT_FAILURE, "setenv(name, value2, 1)");
 
-	gettimeofday(&endTime, NULL);
+	getrusage(RUSAGE_SELF, &endUsage);
 
-	report_time("setenv(name, value2, 1)", &startTime, &endTime);
+	report_time("setenv(name, value2, 1)", &startUsage.ru_utime,
+	    &endUsage.ru_utime);
 
 
 	/*
 	 * getenv() a different variable on the new environment.
 	 */
-	gettimeofday(&startTime, NULL);
+	getrusage(RUSAGE_SELF, &startUsage);
 
 	/* Iterate over setting variable. */
 	for (iterations = 0; iterations < MaxIterations; iterations++)
@@ -155,15 +159,15 @@
 		if (getenv(name2) == NULL)
 			err(EXIT_FAILURE, "getenv(name)");
 
-	gettimeofday(&endTime, NULL);
+	getrusage(RUSAGE_SELF, &endUsage);
 
-	report_time("getenv(name)", &startTime, &endTime);
+	report_time("getenv(name)", &startUsage.ru_utime, &endUsage.ru_utime);
 
 
 	/*
 	 * getenv() a different variable on the new environment.
 	 */
-	gettimeofday(&startTime, NULL);
+	getrusage(RUSAGE_SELF, &startUsage);
 
 	/* Iterate over setting variable. */
 	for (iterations = 0; iterations < MaxIterations; iterations++)
@@ -171,24 +175,25 @@
 		if (getenv(name2) == NULL)
 			err(EXIT_FAILURE, "getenv(name2)");
 
-	gettimeofday(&endTime, NULL);
+	getrusage(RUSAGE_SELF, &endUsage);
 
-	report_time("getenv(name2)", &startTime, &endTime);
+	report_time("getenv(name2)", &startUsage.ru_utime, &endUsage.ru_utime);
 
 
 	/*
 	 * putenv() a variable with a small value.
 	 */
-	gettimeofday(&startTime, NULL);
+	getrusage(RUSAGE_SELF, &startUsage);
 
 	/* Iterate over setting variable. */
 	for (iterations = 0; iterations < MaxIterations; iterations++)
 		if (putenv(nameValuePair) == -1)
 			err(EXIT_FAILURE, "putenv(nameValuePair)");
 
-	gettimeofday(&endTime, NULL);
+	getrusage(RUSAGE_SELF, &endUsage);
 
-	report_time("putenv(nameValuePair)", &startTime, &endTime);
+	report_time("putenv(nameValuePair)", &startUsage.ru_utime,
+	    &endUsage.ru_utime);
 
 
 	exit(EXIT_SUCCESS);