[9front] diff: request for some eyeballs/testing

[ori@eigenstate.org]

as a result of the recent 1oct1993 changes,
I discovered we don't currently handle file->dir
changes correctly in a bunch of our utilities;
diff, patch, and git are all a tad wonky when
it comes to this.

the first, er, diff to diff which should start
helping fix this is below -- it fixes both path
construction and makes it print a file deletion
and addition when a directory is involved in the
diff; patch should then have sufficient info to
apply the diff (though it currently doesn't handle
it correctly).

this fixes diff mis-constructing file paths,


diff 4c6701041ec241bbb900883043790af2fd5e8152 uncommitted
--- a/sys/src/cmd/diff/diffdir.c
+++ b/sys/src/cmd/diff/diffdir.c
@@ -19,14 +19,14 @@
 	int nitems;
 	int fd, n;
 
-	if ((fd = open(name, OREAD)) < 0) {
+	cp = emalloc(sizeof(char*));
+	cp[0] = nil;
+	if(strcmp(name, "/dev/null") == 0)
+		return cp;
+	if((fd = open(name, OREAD)) < 0){
 		fprint(2, "%s: can't open %s: %r\n", argv0, name);
-		/* fake an empty directory */
-		cp = emalloc(sizeof(char*));
-		cp[0] = 0;
 		return cp;
 	}
-	cp = 0;
 	nitems = 0;
 	if((n = dirreadall(fd, &db)) > 0){
 		while (n--) {
@@ -44,18 +44,6 @@
 	return cp;
 }
 
-static int
-isdotordotdot(char *p)
-{
-	if (*p == '.') {
-		if (!p[1])
-			return 1;
-		if (p[1] == '.' && !p[2])
-			return 1;
-	}
-	return 0;
-}
-
 void
 diffdir(char *f, char *t, int level)
 {
@@ -68,17 +56,11 @@
 	dt = scandir(t);
 	dirf = df;
 	dirt = dt;
+	if(level != 0 && !rflag)
+		return;
 	while (*df || *dt) {
 		from = *df;
 		to = *dt;
-		if (from && isdotordotdot(from)) {
-			df++;
-			continue;
-		}
-		if (to && isdotordotdot(to)) {
-			dt++;
-			continue;
-		}
 		if (!from)
 			res = 1;
 		else if (!to)
@@ -86,23 +68,30 @@
 		else
 			res = strcmp(from, to);
 		if (res < 0) {
-			if (mode == 0 || mode == 'n')
+			if (mkpathname(fb, f, from))
+				continue;
+			if(rflag)
+				diff(fb, "/dev/null", level+1);
+			else if(mode == 0 || mode == 'n')
 				Bprint(&stdout, "Only in %s: %s\n", f, from);
 			df++;
-			continue;
-		}
-		if (res > 0) {
+		}else if (res > 0){
+			if (mkpathname(tb, t, to))
+				continue;
+			if(rflag)
+				diff("/dev/null", tb, level+1);
 			if (mode == 0 || mode == 'n')
 				Bprint(&stdout, "Only in %s: %s\n", t, to);
 			dt++;
-			continue;
+		}else{
+			if (mkpathname(fb, f, from))
+				continue;
+			if (mkpathname(tb, t, to))
+				continue;
+			diff(fb, tb, level+1);
+			df++;
+			dt++;
 		}
-		if (mkpathname(fb, f, from))
-			continue;
-		if (mkpathname(tb, t, to))
-			continue;
-		diff(fb, tb, level+1);
-		df++; dt++;
 	}
 	for (df = dirf; *df; df++)
 		free(*df);
@@ -115,7 +104,7 @@
 void
 diff(char *f, char *t, int level)
 {
-	char *fp, *tp, *p, fb[MAXPATHLEN+1], tb[MAXPATHLEN+1];
+	char *fp, *tp;
 	Dir *fsb, *tsb;
 
 	fsb = nil;
@@ -129,24 +118,15 @@
 			diffdir(fp, tp, level);
 		else
 			Bprint(&stdout, "Common subdirectories: %s and %s\n", fp, tp);
-	}
-	else if (REGULAR_FILE(fsb) && REGULAR_FILE(tsb))
+	}else if (REGULAR_FILE(fsb) && REGULAR_FILE(tsb)){
 		diffreg(fp, f, tp, t);
-	else {
-		if (REGULAR_FILE(fsb)) {
-			if ((p = utfrrune(f, '/')) == 0)
-				p = f;
-			else
-				p++;
-			if (mkpathname(tb, tp, p) == 0)
-				diffreg(fp, f, tb, t);
-		} else {
-			if ((p = utfrrune(t, '/')) == 0)
-				p = t;
-			else
-				p++;
-			if (mkpathname(fb, fp, p) == 0)
-				diffreg(fb, f, tp, t);
+	}else{
+		if(REGULAR_FILE(fsb)){
+			diffreg(fp, f, "/dev/null", "/dev/null");
+			diffdir("/dev/null", tp, level);
+		}else{
+			diffdir(fp, "/dev/null", level);
+			diffreg("/dev/null", "/dev/null", tp, t);
 		}
 	}
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