don't crash on truncated log files

Add a test that tries all truncations of a log file and verifies it
doesn't crash.

1 files changed, 7 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);
   }