git: b6b26cecc0ba - stable/13 - diff: simplify the hash functions

[Baptiste Daroussin]

The branch stable/13 has been updated by bapt:

URL: https://cgit.FreeBSD.org/src/commit/?id=b6b26cecc0babc7834c026b43bb761cbd5147ed9

commit b6b26cecc0babc7834c026b43bb761cbd5147ed9
Author:     Baptiste Daroussin <bapt at FreeBSD.org>
AuthorDate: 2021-01-26 15:25:00 +0000
Commit:     Baptiste Daroussin <bapt at FreeBSD.org>
CommitDate: 2021-05-05 08:37:09 +0000

    diff: simplify the hash functions
    
    Instead of 3 different complex case they have all been folded into a
    simple on based on switch
    
    (cherry picked from commit e43239f5140e1b80de122458a2ac037172866058)
---
 usr.bin/diff/diffreg.c | 77 ++++++++++++++++++--------------------------------
 1 file changed, 27 insertions(+), 50 deletions(-)

diff --git a/usr.bin/diff/diffreg.c b/usr.bin/diff/diffreg.c
index 9839171c5639..35d41b28fb7c 100644
--- a/usr.bin/diff/diffreg.c
+++ b/usr.bin/diff/diffreg.c
@@ -1350,64 +1350,41 @@ readhash(FILE *f, int flags)
 
 	sum = 1;
 	space = 0;
-	if ((flags & (D_FOLDBLANKS|D_IGNOREBLANKS)) == 0) {
-		if (flags & D_IGNORECASE)
-			for (i = 0; (t = getc(f)) != '\n'; i++) {
-				if (flags & D_STRIPCR && t == '\r') {
-					t = getc(f);
-					if (t == '\n')
-						break;
-					ungetc(t, f);
-				}
-				if (t == EOF) {
-					if (i == 0)
-						return (0);
+	for (i = 0;;) {
+		switch (t = getc(f)) {
+		case '\r':
+			if (flags & D_STRIPCR) {
+				t = getc(f);
+				if (t == '\n')
 					break;
-				}
-				sum = sum * 127 + chrtran(t);
-			}
-		else
-			for (i = 0; (t = getc(f)) != '\n'; i++) {
-				if (flags & D_STRIPCR && t == '\r') {
-					t = getc(f);
-					if (t == '\n')
-						break;
-					ungetc(t, f);
-				}
-				if (t == EOF) {
-					if (i == 0)
-						return (0);
-					break;
-				}
-				sum = sum * 127 + t;
+				ungetc(t, f);
 			}
-	} else {
-		for (i = 0;;) {
-			switch (t = getc(f)) {
-			case '\r':
-			case '\t':
-			case '\v':
-			case '\f':
-			case ' ':
+			/* FALLTHROUGH */
+		case '\t':
+		case '\v':
+		case '\f':
+		case ' ':
+			if ((flags & (D_FOLDBLANKS|D_IGNOREBLANKS)) != 0) {
 				space++;
 				continue;
-			default:
-				if (space && (flags & D_IGNOREBLANKS) == 0) {
-					i++;
-					space = 0;
-				}
-				sum = sum * 127 + chrtran(t);
+			}
+			/* FALLTHROUGH */
+		default:
+			if (space && (flags & D_IGNOREBLANKS) == 0) {
 				i++;
-				continue;
-			case EOF:
-				if (i == 0)
-					return (0);
-				/* FALLTHROUGH */
-			case '\n':
-				break;
+				space = 0;
 			}
+			sum = sum * 127 + chrtran(t);
+			i++;
+			continue;
+		case EOF:
+			if (i == 0)
+				return (0);
+			/* FALLTHROUGH */
+		case '\n':
 			break;
 		}
+		break;
 	}
 	/*
 	 * There is a remote possibility that we end up with a zero sum.