Merge #13159: Don't close old debug log file handle prematurely when trying to re-open (on SIGHUP)

75ea00f391 Remove unused fsbridge::freopen (practicalswift)
cceedbc4bf Don't close old debug log file handle prematurely when trying to re-open (on SIGHUP) (practicalswift)

Pull request description:

  Don't close old debug log file handle prematurely when trying to re-open (on `SIGHUP`).

  Context: https://github.com/bitcoin/bitcoin/pull/13148#issuecomment-386288606

  Thanks @ajtowns!

Tree-SHA512: c436b4286f00fc428b60269b6d6321f435c72c7ccec3c15b2194aac71196529b30f32c2384b418ffe3ed67ba7ee8ec51f4c9c5748e65945697c0437eafcdacd1

src/fs.cpp

@@ -14,11 +14,6 @@ FILE *fopen(const fs::path& p, const char *mode)
     return ::fopen(p.string().c_str(), mode);
 }
 
-FILE *freopen(const fs::path& p, const char *mode, FILE *stream)
-{
-    return ::freopen(p.string().c_str(), mode, stream);
-}
-
 #ifndef WIN32
 
 static std::string GetErrorReason() {

src/fs.h

@@ -18,7 +18,6 @@ namespace fs = boost::filesystem;
 /** Bridge operations to C stdio */
 namespace fsbridge {
     FILE *fopen(const fs::path& p, const char *mode);
-    FILE *freopen(const fs::path& p, const char *mode, FILE *stream);
 
     class FileLock
     {

src/logging.cpp

@@ -219,13 +219,13 @@ void BCLog::Logger::LogPrintStr(const std::string &str)
             // reopen the log file, if requested
             if (m_reopen_file) {
                 m_reopen_file = false;
-                m_fileout = fsbridge::freopen(m_file_path, "a", m_fileout);
+                FILE* new_fileout = fsbridge::fopen(m_file_path, "a");
-                if (!m_fileout) {
+                if (new_fileout) {
-                    return;
+                    setbuf(new_fileout, nullptr); // unbuffered
+                    fclose(m_fileout);
+                    m_fileout = new_fileout;
                 }
-                setbuf(m_fileout, nullptr); // unbuffered
             }
-
             FileWriteStr(strTimestamped, m_fileout);
         }
     }