Remove trailing newlines from abort message.

The tombstone will add a newline after the abort message, so remove
any trailing newlines before saving/printing.

Bug: 196414062

Test: Unit tests pass.
Test: Set system property debug.debuggerd.translate_proto_to_text to 0
test: and unit tests still pass.
Change-Id: I0d3dc215eb5d8be93d99e5b9d4f0a14b1d61396d
diff --git a/debuggerd/debuggerd_test.cpp b/debuggerd/debuggerd_test.cpp
index f24c4fc..59643d9 100644
--- a/debuggerd/debuggerd_test.cpp
+++ b/debuggerd/debuggerd_test.cpp
@@ -961,6 +961,44 @@
   ASSERT_MATCH(result, R"(Abort message: 'x{4045}')");
 }
 
+TEST_F(CrasherTest, abort_message_newline_trimmed) {
+  int intercept_result;
+  unique_fd output_fd;
+  StartProcess([]() {
+    android_set_abort_message("Message with a newline.\n");
+    abort();
+  });
+  StartIntercept(&output_fd);
+  FinishCrasher();
+  AssertDeath(SIGABRT);
+  FinishIntercept(&intercept_result);
+
+  ASSERT_EQ(1, intercept_result) << "tombstoned reported failure";
+
+  std::string result;
+  ConsumeFd(std::move(output_fd), &result);
+  ASSERT_MATCH(result, R"(Abort message: 'Message with a newline.')");
+}
+
+TEST_F(CrasherTest, abort_message_multiple_newlines_trimmed) {
+  int intercept_result;
+  unique_fd output_fd;
+  StartProcess([]() {
+    android_set_abort_message("Message with multiple newlines.\n\n\n\n\n");
+    abort();
+  });
+  StartIntercept(&output_fd);
+  FinishCrasher();
+  AssertDeath(SIGABRT);
+  FinishIntercept(&intercept_result);
+
+  ASSERT_EQ(1, intercept_result) << "tombstoned reported failure";
+
+  std::string result;
+  ConsumeFd(std::move(output_fd), &result);
+  ASSERT_MATCH(result, R"(Abort message: 'Message with multiple newlines.')");
+}
+
 TEST_F(CrasherTest, abort_message_backtrace) {
   int intercept_result;
   unique_fd output_fd;
diff --git a/debuggerd/libdebuggerd/tombstone.cpp b/debuggerd/libdebuggerd/tombstone.cpp
index 9c01f15..ff03bcd 100644
--- a/debuggerd/libdebuggerd/tombstone.cpp
+++ b/debuggerd/libdebuggerd/tombstone.cpp
@@ -232,6 +232,12 @@
     return;
   }
 
+  // Remove any trailing newlines.
+  size_t index = length;
+  while (index > 0 && (msg[index - 1] == '\0' || msg[index - 1] == '\n')) {
+    --index;
+  }
+  msg[index] = '\0';
   _LOG(log, logtype::HEADER, "Abort message: '%s'\n", &msg[0]);
 }
 
diff --git a/debuggerd/libdebuggerd/tombstone_proto.cpp b/debuggerd/libdebuggerd/tombstone_proto.cpp
index ff12017..0c93c90 100644
--- a/debuggerd/libdebuggerd/tombstone_proto.cpp
+++ b/debuggerd/libdebuggerd/tombstone_proto.cpp
@@ -271,6 +271,13 @@
     return;
   }
 
+  // Remove any trailing newlines.
+  size_t index = msg.size();
+  while (index > 0 && (msg[index - 1] == '\0' || msg[index - 1] == '\n')) {
+    --index;
+  }
+  msg.resize(index);
+
   tombstone->set_abort_message(msg);
 }