From 5e6a533680fc8292c31f31664d80c48440d4a526 Mon Sep 17 00:00:00 2001
From: Abseil Team <absl-team@google.com>
Date: Tue, 10 May 2022 22:42:35 -0700
Subject: [PATCH] Do a consistent way of searching for a temporary directory.

The way temporary directories were discovered from
environment variables in different operating systems
was inconsistent.

On Windows, only the system-specific environment variable
TEMP was considered, but not the bazel-common TEST_TMPDIR.
On Unix, only TEST_TMPDIR was considered, but not
the otherwise typical system specific TMPDIR.

Now, always consider TEST_TMPDIR first, followed by the
system-typical environment variable (TEMP on Windows, TMPDIR on Unix)
before falling back to a default on that particular system.

Also: the value for the temporary directory coming from the
environment variable was only checked for a trailing directory
separator on Windows (and appended if needed), not on the other
platforms.
Make this also consistent accross the systems: Now always apply
the same logic to all of these (to accomodate
tests that just concatenate TempDir() without directory separator).
PiperOrigin-RevId: 447909830
Change-Id: I9ea17acdf5944eb2a965615fd9cf142878c33a58
---
 googletest/src/gtest.cc | 51 +++++++++++++++++++++--------------------
 1 file changed, 26 insertions(+), 25 deletions(-)

diff --git a/googletest/src/gtest.cc b/googletest/src/gtest.cc
index 73312d4c..1acad59a 100644
--- a/googletest/src/gtest.cc
+++ b/googletest/src/gtest.cc
@@ -44,6 +44,7 @@
 #include <chrono>  // NOLINT
 #include <cmath>
 #include <cstdint>
+#include <initializer_list>
 #include <iomanip>
 #include <iterator>
 #include <limits>
@@ -6745,36 +6746,36 @@ void InitGoogleTest() {
 #endif  // defined(GTEST_CUSTOM_INIT_GOOGLE_TEST_FUNCTION_)
 }
 
+#if !defined(GTEST_CUSTOM_TEMPDIR_FUNCTION_)
+// Return value of first environment variable that is set and contains
+// a non-empty string. If there are none, return the "fallback" string.
+// Since we like the temporary directory to have a directory separator suffix,
+// add it if not provided in the environment variable value.
+static std::string GetTempDirFromEnv(
+    std::initializer_list<const char*> environment_variables,
+    const char* fallback, char separator) {
+  for (const char* variable_name : environment_variables) {
+    const char* value = internal::posix::GetEnv(variable_name);
+    if (value != nullptr && value[0] != '\0') {
+      if (value[strlen(value) - 1] != separator) {
+        return std::string(value).append(1, separator);
+      }
+      return value;
+    }
+  }
+  return fallback;
+}
+#endif
+
 std::string TempDir() {
 #if defined(GTEST_CUSTOM_TEMPDIR_FUNCTION_)
   return GTEST_CUSTOM_TEMPDIR_FUNCTION_();
-#elif GTEST_OS_WINDOWS_MOBILE
-  return "\\temp\\";
-#elif GTEST_OS_WINDOWS
-  const char* temp_dir = internal::posix::GetEnv("TEMP");
-  if (temp_dir == nullptr || temp_dir[0] == '\0') {
-    return "\\temp\\";
-  } else if (temp_dir[strlen(temp_dir) - 1] == '\\') {
-    return temp_dir;
-  } else {
-    return std::string(temp_dir) + "\\";
-  }
+#elif GTEST_OS_WINDOWS || GTEST_OS_WINDOWS_MOBILE
+  return GetTempDirFromEnv({"TEST_TMPDIR", "TEMP"}, "\\temp\\", '\\');
 #elif GTEST_OS_LINUX_ANDROID
-  const char* temp_dir = internal::posix::GetEnv("TEST_TMPDIR");
-  if (temp_dir == nullptr || temp_dir[0] == '\0') {
-    return "/data/local/tmp/";
-  } else {
-    return temp_dir;
-  }
-#elif GTEST_OS_LINUX || GTEST_OS_MAC
-  const char* temp_dir = internal::posix::GetEnv("TEST_TMPDIR");
-  if (temp_dir == nullptr || temp_dir[0] == '\0') {
-    return "/tmp/";
-  } else {
-    return temp_dir;
-  }
+  return GetTempDirFromEnv({"TEST_TMPDIR", "TMPDIR"}, "/data/local/tmp/", '/');
 #else
-  return "/tmp/";
+  return GetTempDirFromEnv({"TEST_TMPDIR", "TMPDIR"}, "/tmp/", '/');
 #endif
 }