handle nuls more carefully in re2c rules

- '.' in re2c matches anything except \n, which means it matches \000.
  Be more careful about which characters we match.
- The fallback rule [^] reads ahead another character, which means it
  can read past the trailing \000.  Add a separate rule to match it
  specifically.

This was found by Valgrind.

1 files changed, 5 insertions, 1 deletions

diff --git a/src/depfile_parser.in.cc b/src/depfile_parser.in.cc
index c469a2c..b310c58 100644
--- a/src/depfile_parser.in.cc
+++ b/src/depfile_parser.in.cc
@@ -55,6 +55,7 @@ bool DepfileParser::Parse(string* content, string* err) {
 
       re2c:yych:emit = 0;
 
+      nul = "\000";
       escape = [ \\#*$[|];
 
       '\\' escape {
@@ -62,7 +63,7 @@ bool DepfileParser::Parse(string* content, string* err) {
         *out++ = yych;
         continue;
       }
-      '\\'. {
+      '\\'[^\000\n] {
         // Let backslash before other characters through verbatim.
         *out++ = '\\';
         *out++ = yych;
@@ -76,6 +77,9 @@ bool DepfileParser::Parse(string* content, string* err) {
         out += len;
         continue;
       }
+      nul {
+        break;
+      }
       [^] {
         // For any other character (e.g. whitespace), swallow it here,
         // allowing the outer logic to loop around again.