Display the actual error code when RE::Init() fails

PiperOrigin-RevId: 865923485
Change-Id: I5530050f7ff3fe295e2bbd7ad0dd90cd0de3e2c3

googletest/src/gtest-port.cc

diff --git a/googletest/src/gtest-port.cc b/googletest/src/gtest-port.cc
index d50d07c..f8ecb37 100644
--- a/googletest/src/gtest-port.cc
+++ b/googletest/src/gtest-port.cc
@@ -89,6 +89,7 @@
 
 #include "gtest/gtest-message.h"
 #include "gtest/gtest-spi.h"
+#include "gtest/gtest.h"
 #include "gtest/internal/gtest-internal.h"
 #include "gtest/internal/gtest-string.h"
 #include "src/gtest-internal-inl.h"
@@ -729,7 +730,7 @@
   char* const full_pattern = new char[full_regex_len];
 
   snprintf(full_pattern, full_regex_len, "^(%s)$", regex);
-  is_valid_ = regcomp(&full_regex_, full_pattern, reg_flags) == 0;
+  int error = regcomp(&full_regex_, full_pattern, reg_flags);
   // We want to call regcomp(&partial_regex_, ...) even if the
   // previous expression returns false.  Otherwise partial_regex_ may
   // not be properly initialized can may cause trouble when it's
@@ -738,13 +739,13 @@
   // Some implementation of POSIX regex (e.g. on at least some
   // versions of Cygwin) doesn't accept the empty string as a valid
   // regex.  We change it to an equivalent form "()" to be safe.
-  if (is_valid_) {
+  if (!error) {
     const char* const partial_regex = (*regex == '\0') ? "()" : regex;
-    is_valid_ = regcomp(&partial_regex_, partial_regex, reg_flags) == 0;
+    error = regcomp(&partial_regex_, partial_regex, reg_flags);
   }
-  EXPECT_TRUE(is_valid_)
-      << "Regular expression \"" << regex
-      << "\" is not a valid POSIX Extended regular expression.";
+  is_valid_ = error == 0;
+  EXPECT_EQ(error, 0) << "Regular expression \"" << regex
+                      << "\" is not a valid POSIX Extended regular expression.";
 
   delete[] full_pattern;
 }