Slightly better handling of NULL bytes

3 files changed, 6 insertions, 5 deletions

diff --git a/file_loader.c b/file_loader.c
index 5d231d3..0ce4b4c 100644
--- a/file_loader.c
+++ b/file_loader.c
@@ -33,6 +33,7 @@ file_t *load_file(const char *filename)
             f->contents = realloc(f->contents, sizeof(char)*(capacity *= 2) + 1);
     }
     f->contents[f->length] = '\0';
+    f->end = &f->contents[f->length];
     close(fd);
     
     // Calculate line numbers:
diff --git a/file_loader.h b/file_loader.h
index 37399ae..a93c7a3 100644
--- a/file_loader.h
+++ b/file_loader.h
@@ -8,7 +8,7 @@
 
 typedef struct {
     const char *filename;
-    char *contents, **lines;
+    char *contents, **lines, *end;
     size_t length, nlines;
     unsigned int mmapped:1;
 } file_t;
diff --git a/vm.c b/vm.c
index c57d6c3..2fb78be 100644
--- a/vm.c
+++ b/vm.c
@@ -83,7 +83,7 @@ static match_t *_match(grammar_t *g, file_t *f, const char *str, vm_op_t *op, un
 {
     switch (op->op) {
         case VM_ANYCHAR: {
-            if (!*str || (!op->multiline && *str == '\n'))
+            if (str >= f->end - 1 || (!op->multiline && *str == '\n'))
                 return NULL;
             match_t *m = calloc(sizeof(match_t), 1);
             m->op = op;
@@ -138,14 +138,14 @@ static match_t *_match(grammar_t *g, file_t *f, const char *str, vm_op_t *op, un
                     // This isn't in the for() structure because there needs to
                     // be at least once chance to match the pattern, even if
                     // we're at the end of the string already (e.g. "..$").
-                    if (*str && (op->multiline || *str != '\n')) ++str;
+                    if (str < f->end && (op->multiline || *str != '\n')) ++str;
                 }
                 destroy_match(&m);
                 return NULL;
             } else if (op->multiline) {
-                while (*str) ++str;
+                str = f->end;
             } else {
-                while (*str && *str != '\n') ++str;
+                while (str < f->end && *str != '\n') ++str;
             }
             m->end = str;
             return m;