1 files changed, 30 insertions, 6 deletions

diff --git a/git-compat-util.h b/git-compat-util.h
index 4b7dcf21ad..047172d173 100644
--- a/git-compat-util.h
+++ b/git-compat-util.h
@@ -693,10 +693,12 @@ char *gitstrdup(const char *s);
 #endif
 
 #ifdef FREAD_READS_DIRECTORIES
-#ifdef fopen
-#undef fopen
-#endif
-#define fopen(a,b) git_fopen(a,b)
+# if !defined(SUPPRESS_FOPEN_REDEFINITION)
+#  ifdef fopen
+#   undef fopen
+#  endif
+#  define fopen(a,b) git_fopen(a,b)
+# endif
 extern FILE *git_fopen(const char*, const char*);
 #endif
 
@@ -804,6 +806,13 @@ extern int xmkstemp(char *template);
 extern int xmkstemp_mode(char *template, int mode);
 extern char *xgetcwd(void);
 extern FILE *fopen_for_writing(const char *path);
+extern FILE *fopen_or_warn(const char *path, const char *mode);
+
+/*
+ * FREE_AND_NULL(ptr) is like free(ptr) followed by ptr = NULL. Note
+ * that ptr is used twice, so don't pass e.g. ptr++.
+ */
+#define FREE_AND_NULL(p) do { free(p); (p) = NULL; } while (0)
 
 #define ALLOC_ARRAY(x, alloc) (x) = xmalloc(st_mult(sizeof(*(x)), (alloc)))
 #define REALLOC_ARRAY(x, alloc) (x) = xrealloc((x), st_mult(sizeof(*(x)), (alloc)))
@@ -1110,8 +1119,8 @@ int remove_or_warn(unsigned int mode, const char *path);
 int access_or_warn(const char *path, int mode, unsigned flag);
 int access_or_die(const char *path, int mode, unsigned flag);
 
-/* Warn on an inaccessible file that ought to be accessible */
-void warn_on_inaccessible(const char *path);
+/* Warn on an inaccessible file if errno indicates this is an error */
+int warn_on_fopen_errors(const char *path);
 
 #ifdef GMTIME_UNRELIABLE_ERRORS
 struct tm *git_gmtime(const time_t *);
@@ -1134,6 +1143,21 @@ struct tm *git_gmtime_r(const time_t *, struct tm *);
 #define getc_unlocked(fh) getc(fh)
 #endif
 
+/*
+ * Our code often opens a path to an optional file, to work on its
+ * contents when we can successfully open it.  We can ignore a failure
+ * to open if such an optional file does not exist, but we do want to
+ * report a failure in opening for other reasons (e.g. we got an I/O
+ * error, or the file is there, but we lack the permission to open).
+ *
+ * Call this function after seeing an error from open() or fopen() to
+ * see if the errno indicates a missing file that we can safely ignore.
+ */
+static inline int is_missing_file_error(int errno_)
+{
+	return (errno_ == ENOENT || errno_ == ENOTDIR);
+}
+
 extern int cmd_main(int, const char **);
 
 #endif