Win32: fix environment memory leaks

kblees · gitster · commit e96942e821de · 2014-07-21T09:32:49.000-07:00
All functions that modify the environment have memory leaks. Disable gitunsetenv in the Makefile and use env_setenv (via mingw_putenv) instead (this frees removed environment entries). Move xstrdup from env_setenv to make_augmented_environ, so that mingw_putenv no longer copies the environment entries (according to POSIX [1], "the string [...] shall become part of the environment"). This also fixes the memory leak in gitsetenv, which expects a POSIX compliant putenv. [1] http://pubs.opengroup.org/onlinepubs/009695399/functions/putenv.html Note: This patch depends on taking control of char **environ and having our own mingw_putenv (both introduced in "Win32: Unicode environment (incoming)"). Signed-off-by: Karsten Blees <blees@dcon.de> Signed-off-by: Stepan Kasal <kasal@ucw.cz> Signed-off-by: Junio C Hamano <gitster@pobox.com>
diff --git a/compat/mingw.c b/compat/mingw.c
@@ -1220,14 +1220,14 @@ static char **env_setenv(char **env, const char *name)
 			for (i = 0; env[i]; i++)
 				;
 			env = xrealloc(env, (i+2)*sizeof(*env));
-			env[i] = xstrdup(name);
+			env[i] = (char*) name;
 			env[i+1] = NULL;
 		}
 	}
 	else {
 		free(env[i]);
 		if (*eq)
-			env[i] = xstrdup(name);
+			env[i] = (char*) name;
 		else
 			for (; env[i]; i++)
 				env[i] = env[i+1];
@@ -1242,8 +1242,10 @@ char **make_augmented_environ(const char *const *vars)
 {
 	char **env = copy_environ();
 
-	while (*vars)
-		env = env_setenv(env, *vars++);
+	while (*vars) {
+		const char *v = *vars++;
+		env = env_setenv(env, strchr(v, '=') ? xstrdup(v) : v);
+	}
 	return env;
 }
 
diff --git a/compat/mingw.h b/compat/mingw.h
@@ -209,6 +209,7 @@ char *mingw_getenv(const char *name);
 #define getenv mingw_getenv
 int mingw_putenv(const char *namevalue);
 #define putenv mingw_putenv
+#define unsetenv mingw_putenv
 
 int mingw_gethostname(char *host, int namelen);
 #define gethostname mingw_gethostname
diff --git a/config.mak.uname b/config.mak.uname
@@ -326,7 +326,6 @@ ifeq ($(uname_S),Windows)
 	NO_IPV6 = YesPlease
 	NO_UNIX_SOCKETS = YesPlease
 	NO_SETENV = YesPlease
-	NO_UNSETENV = YesPlease
 	NO_STRCASESTR = YesPlease
 	NO_STRLCPY = YesPlease
 	NO_MEMMEM = YesPlease
@@ -479,7 +478,6 @@ ifneq (,$(findstring MINGW,$(uname_S)))
 	NO_SYMLINK_HEAD = YesPlease
 	NO_UNIX_SOCKETS = YesPlease
 	NO_SETENV = YesPlease
-	NO_UNSETENV = YesPlease
 	NO_STRCASESTR = YesPlease
 	NO_STRLCPY = YesPlease
 	NO_MEMMEM = YesPlease

Original file line number	Diff line number	Diff line change
`@@ -1220,14 +1220,14 @@ static char env_setenv(char env, const char *name)`
`1220`	`1220`	`for (i = 0; env[i]; i++)`
`1221`	`1221`	`;`
`1222`	`1222`	`env = xrealloc(env, (i+2)sizeof(env));`
`1223`		`- env[i] = xstrdup(name);`
	`1223`	`+ env[i] = (char*) name;`
`1224`	`1224`	`env[i+1] = NULL;`
`1225`	`1225`	`}`
`1226`	`1226`	`}`
`1227`	`1227`	`else {`
`1228`	`1228`	`free(env[i]);`
`1229`	`1229`	`if (*eq)`
`1230`		`- env[i] = xstrdup(name);`
	`1230`	`+ env[i] = (char*) name;`
`1231`	`1231`	`else`
`1232`	`1232`	`for (; env[i]; i++)`
`1233`	`1233`	`env[i] = env[i+1];`
`@@ -1242,8 +1242,10 @@ char *make_augmented_environ(const char const *vars)`
`1242`	`1242`	`{`
`1243`	`1243`	`char **env = copy_environ();`
`1244`	`1244`
`1245`		`- while (*vars)`
`1246`		`- env = env_setenv(env, *vars++);`
	`1245`	`+ while (*vars) {`
	`1246`	`+ const char v = vars++;`
	`1247`	`+ env = env_setenv(env, strchr(v, '=') ? xstrdup(v) : v);`
	`1248`	`+ }`
`1247`	`1249`	`return env;`
`1248`	`1250`	`}`
`1249`	`1251`