2 files changed, 35 insertions, 3 deletions
diff --git a/src/build_log.cc b/src/build_log.cc
index cd74bd1..c630fbe 100644
--- a/src/build_log.cc
+++ b/src/build_log.cc
@@ -144,8 +144,15 @@ bool BuildLog::Load(const string& path, string* err) {
     }
 
     end = strchr(start, ' ');
+    if (!end)
+      continue;
     string output = string(start, end - start);
 
+    start = end + 1;
+    end = strchr(start, '\n');
+    if (!end)
+      continue;
+
     LogEntry* entry;
     Log::iterator i = log_.find(output);
     if (i != log_.end()) {
@@ -160,9 +167,6 @@ bool BuildLog::Load(const string& path, string* err) {
     entry->output = output;
     entry->start_time = start_time;
     entry->end_time = end_time;
-
-    start = end + 1;
-    end = strchr(start, '\n');
     entry->command = string(start, end - start);
   }
 
diff --git a/src/build_log_test.cc b/src/build_log_test.cc
index caf1540..8bb2bfa 100644
--- a/src/build_log_test.cc
+++ b/src/build_log_test.cc
@@ -69,3 +69,31 @@ TEST_F(BuildLogTest, DoubleEntry) {
   ASSERT_TRUE(e);
   ASSERT_EQ("command def", e->command);
 }
+
+TEST_F(BuildLogTest, Truncate) {
+  AssertParse(&state_,
+"build out: cat mid\n"
+"build mid: cat in\n");
+
+  BuildLog log1;
+  string err;
+  EXPECT_TRUE(log1.OpenForWrite(kTestFilename, &err));
+  ASSERT_EQ("", err);
+  log1.RecordCommand(state_.edges_[0], 15, 18);
+  log1.RecordCommand(state_.edges_[1], 20, 25);
+  log1.Close();
+
+  struct stat statbuf;
+  ASSERT_EQ(0, stat(kTestFilename, &statbuf));
+  ASSERT_GT(statbuf.st_size, 0);
+
+  // For all possible truncations of the input file, assert that we don't
+  // crash or report an error when parsing.
+  for (off_t size = statbuf.st_size; size > 0; --size) {
+    ASSERT_EQ(0, truncate(kTestFilename, size));
+
+    BuildLog log2;
+    EXPECT_TRUE(log2.Load(kTestFilename, &err));
+    ASSERT_EQ("", err);
+  }
+}