Avoid dialogs and generating call stacks under a debugger

base/logging.cc

Index: base/logging.cc
diff --git a/base/logging.cc b/base/logging.cc
index ea731610dd59fe1006f9a11d89a10589b3ffe08a..57c332640443644878601865e0d10499307b6b3b 100644
--- a/base/logging.cc
+++ b/base/logging.cc
@@ -545,10 +545,12 @@ LogMessage::LogMessage(const char* file, int line, LogSeverity severity,
 LogMessage::~LogMessage() {
 #if !defined(OFFICIAL_BUILD) && !defined(OS_NACL) && !defined(__UCLIBC__)
   if (severity_ == LOG_FATAL) {
-    // Include a stack trace on a fatal.
-    base::debug::StackTrace trace;
-    stream_ << std::endl;  // Newline to separate from log message.
-    trace.OutputToStream(&stream_);
+    if (!base::debug::BeingDebugged()) {

[Lei Zhang, 2015/09/04 22:11:31]

nit: combine with the if on the line above?

+      // Include a stack trace on a fatal, unless a debugger is attached.
+      base::debug::StackTrace trace;
+      stream_ << std::endl;  // Newline to separate from log message.
+      trace.OutputToStream(&stream_);
+    }
   }
 #endif
   stream_ << std::endl;
@@ -639,7 +641,11 @@ LogMessage::~LogMessage() {
       // information, and displaying message boxes when the application is
       // hosed can cause additional problems.
 #ifndef NDEBUG
-      DisplayDebugMessageInDialog(stream_.str());
+      if (!base::debug::BeingDebugged()) {
+        // Displaying a dialog is unnecessary when debugging and can complicate
+        // debugging.
+        DisplayDebugMessageInDialog(stream_.str());
+      }
 #endif
       // Crash the process to generate a dump.
       base::debug::BreakDebugger();