Include pathname in exception thrown in File::rw_lock

CHANGELOG.md

@@ -6,9 +6,10 @@
 
 ### Fixed
 * <How do the end-user experience this issue? what was the impact?> ([#????](https://github.com/realm/realm-core/issues/????), since v?.?.?)
-* Using an empty KeyPath in C API would result in no filtering being done ([#7805](https://github.com/realm/realm-core/issues/7805), since 13.24.0)
-* Filtering notifications with backlink columns as last element could sometimes give wrong results ([#7530](https://github.com/realm/realm-core/issues/7530), since 11.1.0)
+* Using an empty KeyPath in C API would result in no filtering being done ([#7805](https://github.com/realm/realm-core/issues/7805), since v13.24.0)
+* Filtering notifications with backlink columns as last element could sometimes give wrong results ([#7530](https://github.com/realm/realm-core/issues/7530), since v11.1.0)
 * Fix crash during client app shutdown when Logger log level is set higher than Info. ([#7969](https://github.com/realm/realm-core/issues/7969), since v13.23.3)
+* If File::rw_lock() fails to open a file the exception message does not contain the filename ([#7999](https://github.com/realm/realm-core/issues/7999), since v6.0.21)
 
 ### Breaking changes
 * None.

src/realm/util/file.cpp

@@ -1152,6 +1152,11 @@ bool File::rw_lock(bool exclusive, bool non_blocking)
     // or the OS will deadlock when un-suspending the app.
     int mode = exclusive ? O_WRONLY | O_NONBLOCK : O_RDWR | O_NONBLOCK;
 
+    auto report_err = [path = m_fifo_path](int err, const char* msg) {
+        auto message = util::format("%1: %2, path = '%3'", msg, std::system_category().message(err), path);
+        throw RuntimeError(ErrorCodes::FileOperationFailed, message); // LCOV_EXCL_LINE
+    };
+
     // Optimistically try to open the fifo. This may fail due to the fifo not
     // existing, but since it usually exists this is faster than trying to create
     // it first.
@@ -1168,7 +1173,7 @@ bool File::rw_lock(bool exclusive, bool non_blocking)
             }
 
             // Otherwise we got an unexpected error
-            throw std::system_error(err, std::system_category(), "opening lock fifo for writing failed");
+            report_err(err, "opening lock fifo for writing failed");
         }
 
         if (err == ENOENT) {
@@ -1178,15 +1183,15 @@ bool File::rw_lock(bool exclusive, bool non_blocking)
                 try_make_dir(m_fifo_dir_path);
             status = mkfifo(m_fifo_path.c_str(), 0666);
             if (status != 0)
-                throw std::system_error(errno, std::system_category(), "creating lock fifo for reading failed");
+                report_err(errno, "creating lock fifo for reading failed");
 
             // Try again to open the fifo now that it exists
             fd = ::open(m_fifo_path.c_str(), mode);
             err = errno;
         }
 
         if (fd == -1)
-            throw std::system_error(err, std::system_category(), "opening lock fifo for reading failed");
+            report_err(err, "opening lock fifo for reading failed");
     }
 
     // We successfully opened the pipe. If we're trying to acquire an exclusive