LibC+Tests: Simplify getpwuid_r() and getpwnam_r() and add tests

These functions are now implemented in terms of getpwent_r() which
allows us to remove two FIXMEs about global variable shenanigans.

I'm also adding tests for both APIs. :^)

1 files changed, 14 insertions, 83 deletions

diff --git a/Userland/Libraries/LibC/pwd.cpp b/Userland/Libraries/LibC/pwd.cpp
index 688d3f306c..12aed49973 100644
--- a/Userland/Libraries/LibC/pwd.cpp
+++ b/Userland/Libraries/LibC/pwd.cpp
@@ -20,12 +20,6 @@ extern "C" {
 static FILE* s_stream = nullptr;
 static unsigned s_line_number = 0;
 
-static String s_name;
-static String s_passwd;
-static String s_gecos;
-static String s_dir;
-static String s_shell;
-
 void setpwent()
 {
     s_line_number = 0;
@@ -163,91 +157,28 @@ int getpwent_r(struct passwd* passwd_buf, char* buffer, size_t buffer_size, stru
     }
 }
 
-static void construct_pwd(struct passwd* pwd, char* buf, struct passwd** result)
-{
-    auto* buf_name = &buf[0];
-    auto* buf_passwd = &buf[s_name.length() + 1];
-    auto* buf_gecos = &buf[s_name.length() + 1 + s_gecos.length() + 1];
-    auto* buf_dir = &buf[s_gecos.length() + 1 + s_name.length() + 1 + s_gecos.length() + 1];
-    auto* buf_shell = &buf[s_dir.length() + 1 + s_gecos.length() + 1 + s_name.length() + 1 + s_gecos.length() + 1];
-
-    bool ok = true;
-    ok = ok && s_name.copy_characters_to_buffer(buf_name, s_name.length() + 1);
-    ok = ok && s_passwd.copy_characters_to_buffer(buf_passwd, s_passwd.length() + 1);
-    ok = ok && s_gecos.copy_characters_to_buffer(buf_gecos, s_gecos.length() + 1);
-    ok = ok && s_dir.copy_characters_to_buffer(buf_dir, s_dir.length() + 1);
-    ok = ok && s_shell.copy_characters_to_buffer(buf_shell, s_shell.length() + 1);
-
-    VERIFY(ok);
-
-    *result = pwd;
-    pwd->pw_name = buf_name;
-    pwd->pw_passwd = buf_passwd;
-    pwd->pw_gecos = buf_gecos;
-    pwd->pw_dir = buf_dir;
-    pwd->pw_shell = buf_shell;
-}
-
-int getpwnam_r(char const* name, struct passwd* pwd, char* buf, size_t buflen, struct passwd** result)
+// https://pubs.opengroup.org/onlinepubs/9699919799/functions/getpwnam.html
+int getpwnam_r(char const* name, struct passwd* pwd, char* buffer, size_t bufsize, struct passwd** result)
 {
-    // FIXME: This is a HACK!
-    TemporaryChange name_change { s_name, {} };
-    TemporaryChange passwd_change { s_passwd, {} };
-    TemporaryChange gecos_change { s_gecos, {} };
-    TemporaryChange dir_change { s_dir, {} };
-    TemporaryChange shell_change { s_shell, {} };
-
     setpwent();
-    bool found = false;
-    while (auto* pw = getpwent()) {
-        if (!strcmp(pw->pw_name, name)) {
-            found = true;
-            break;
-        }
-    }
-
-    if (!found) {
-        *result = nullptr;
-        return 0;
+    for (;;) {
+        if (auto rc = getpwent_r(pwd, buffer, bufsize, result); rc != 0)
+            return rc;
+        if (strcmp(pwd->pw_name, name) == 0)
+            return 0;
     }
-
-    auto const total_buffer_length = s_name.length() + s_passwd.length() + s_gecos.length() + s_dir.length() + s_shell.length() + 5;
-    if (buflen < total_buffer_length)
-        return ERANGE;
-
-    construct_pwd(pwd, buf, result);
-    return 0;
 }
 
-int getpwuid_r(uid_t uid, struct passwd* pwd, char* buf, size_t buflen, struct passwd** result)
+// https://pubs.opengroup.org/onlinepubs/9699919799/functions/getpwuid.html
+int getpwuid_r(uid_t uid, struct passwd* pwd, char* buffer, size_t bufsize, struct passwd** result)
 {
-    // FIXME: This is a HACK!
-    TemporaryChange name_change { s_name, {} };
-    TemporaryChange passwd_change { s_passwd, {} };
-    TemporaryChange gecos_change { s_gecos, {} };
-    TemporaryChange dir_change { s_dir, {} };
-    TemporaryChange shell_change { s_shell, {} };
-
     setpwent();
-    bool found = false;
-    while (auto* pw = getpwent()) {
-        if (pw->pw_uid == uid) {
-            found = true;
-            break;
-        }
-    }
-
-    if (!found) {
-        *result = nullptr;
-        return 0;
+    for (;;) {
+        if (auto rc = getpwent_r(pwd, buffer, bufsize, result); rc != 0)
+            return rc;
+        if (pwd->pw_uid == uid)
+            return 0;
     }
-
-    auto const total_buffer_length = s_name.length() + s_passwd.length() + s_gecos.length() + s_dir.length() + s_shell.length() + 5;
-    if (buflen < total_buffer_length)
-        return ERANGE;
-
-    construct_pwd(pwd, buf, result);
-    return 0;
 }
 
 int putpwent(const struct passwd* p, FILE* stream)