Merge branch 'bc/fopen'

* bc/fopen:
  Add compat/fopen.c which returns NULL on attempt to open directory

compat/fopen.c

@@ -0,0 +1,26 @@
+#include "../git-compat-util.h"
+#undef fopen
+FILE *git_fopen(const char *path, const char *mode)
+{
+	FILE *fp;
+	struct stat st;
+
+	if (mode[0] == 'w' || mode[0] == 'a')
+		return fopen(path, mode);
+
+	if (!(fp = fopen(path, mode)))
+		return NULL;
+
+	if (fstat(fileno(fp), &st)) {
+		fclose(fp);
+		return NULL;
+	}
+
+	if (S_ISDIR(st.st_mode)) {
+		fclose(fp);
+		errno = EISDIR;
+		return NULL;
+	}
+
+	return fp;
+}