builtin/commit.c: extract ignore_non_trailer() helper function

diff --git a/xdiff/xmacros.h b/xdiff/xmacros.h
index 4c2fde80c143b3aaf086dc36c1a050851f83feaa..165a895a93e04b33ca7c8f3839ee85e0eccb4a07 100644 (file)
--- a/xdiff/xmacros.h
+++ b/xdiff/xmacros.h
@@ -24,14 +24,16 @@
 #define XMACROS_H
 
 
-#define GR_PRIME 0x9e370001UL
 
 
 #define XDL_MIN(a, b) ((a) < (b) ? (a): (b))
 #define XDL_MAX(a, b) ((a) > (b) ? (a): (b))
 #define XDL_ABS(v) ((v) >= 0 ? (v): -(v))
 #define XDL_ISDIGIT(c) ((c) >= '0' && (c) <= '9')
-#define XDL_HASHLONG(v, b) (((unsigned long)(v) * GR_PRIME) >> ((CHAR_BIT * sizeof(unsigned long)) - (b)))
+#define XDL_ISSPACE(c) (isspace((unsigned char)(c)))
+#define XDL_ADDBITS(v,b)       ((v) + ((v) >> (b)))
+#define XDL_MASKBITS(b)                ((1UL << (b)) - 1)
+#define XDL_HASHLONG(v,b)      (XDL_ADDBITS((unsigned long)(v), b) & XDL_MASKBITS(b))
 #define XDL_PTRFREE(p) do { if (p) { xdl_free(p); (p) = NULL; } } while (0)
 #define XDL_LE32_PUT(p, v) \
 do { \
@@ -50,4 +52,3 @@ do { \
 
 
 #endif /* #if !defined(XMACROS_H) */
-