Am 06.04.2017 um 18:34 schrieb g...@jeffhostetler.com:
diff --git a/read-cache.c b/read-cache.c
index 9054369..e8f1900 100644
--- a/read-cache.c
+++ b/read-cache.c
@@ -887,6 +887,26 @@ static int has_file_name(struct index_state *istate,
return retval;
}
+
+/*
+ * Like strcmp(), but also return the offset of the first change.
+ * If strings are equal, return the length.
+ */
+int strcmp_offset(const char *s1, const char *s2, int *first_change)
+{
+ int k;
+
+ if (!first_change)
+ return strcmp(s1, s2);
+
+ for (k = 0; s1[k] == s2[k]; k++)
+ if (s1[k] == '\0')
+ break;
+
+ *first_change = k;
+ return ((unsigned char *)s1)[k] - ((unsigned char *)s2)[k];
+}
I like how this is shaping up to become a reusable function, but I only
found one other possible use case (in read-cache.c::ce_write_entry),
which somehow irritates me. Either I didn't look hard enough (likely),
we haven't got fitting code just yet, or this function isn't meant to be
exported -- in the latter case its interface doesn't have to be polished
as much. (Just a thought, don't let me stop you.)
Assuming strcmp_offset() is a library-grade function then its
first_change parameter should point to a size_t instead of an int, no?
Casting away the const qualifier in the return line is a bit iffy. Why
not cast after dereferencing, like this?
return (unsigned char)s1[k] - (unsigned char)s2[k];
René
