From: NeilBrown <neilb@suse.de>
Date: Tue, 20 Aug 2013 05:29:53 +0000 (+1000)
Subject: Make some fatal errors more helpful.
X-Git-Tag: v1.0~30
X-Git-Url: http://git.neil.brown.name/?a=commitdiff_plain;h=97f2558129ab118fadce95b45a93b7f63a2cbcbd;p=wiggle.git

Make some fatal errors more helpful.

Complain sensibly if something is a directory, and
mention that read or malloc failed if it did.

Signed-off-by: NeilBrown <neilb@suse.de>
---

diff --git a/load.c b/load.c
index 2dfa846..108b644 100644
--- a/load.c
+++ b/load.c
@@ -54,7 +54,7 @@ static void join_streams(struct stream list[], int cnt)
 
 	c = realloc(list[0].body, len+1);
 	if (c == NULL)
-		die();
+		die("memory allocation");
 
 	list[0].body = c;
 	c  += list[0].len;
@@ -77,7 +77,7 @@ static struct stream load_regular(int fd)
 	s.len = stb.st_size;
 	s.body = xmalloc(s.len+1);
 	if (read(fd, s.body, s.len) != s.len)
-		die();
+		die("file read");
 
 	s.body[s.len] = 0;
 	return s;
@@ -93,7 +93,7 @@ static struct stream load_other(int fd)
 		list[i].body = xmalloc(8192);
 		list[i].len = read(fd, list[i].body, 8192);
 		if (list[i].len < 0)
-			die();
+			die("file read");
 		if (list[i].len == 0)
 			break;
 		i++;
@@ -114,7 +114,7 @@ struct stream load_segment(FILE *f,
 	s.body = xmalloc(s.len+1);
 	fseek(f, start, 0);
 	if (fread(s.body, 1, s.len, f) != (size_t)s.len)
-		die();
+		die("file read");
 	/* ensure string is 'nul' terminated - for sscanf */
 	s.body[s.len] = 0;
 	return s;
@@ -148,7 +148,7 @@ struct stream load_file(char *name)
 			if (fd < 0)
 				return s;
 		}
-
+		check_dir(name, fd);
 		if (fstat(fd, &stb) == 0) {
 
 			if (S_ISREG(stb.st_mode))
diff --git a/vpatch.c b/vpatch.c
index f93b522..bca7533 100644
--- a/vpatch.c
+++ b/vpatch.c
@@ -3059,6 +3059,7 @@ int vpatch(int argc, char *argv[], int patch, int strip,
 			fprintf(stderr, "%s: cannot open %s\n", Cmd, argv[0]);
 			exit(1);
 		}
+		check_dir(argv[0], fileno(f));
 		if (patch) {
 			pl = parse_patch(f, NULL, &num_patches);
 			if (set_prefix(pl, num_patches, strip) == 0) {
@@ -3080,6 +3081,7 @@ int vpatch(int argc, char *argv[], int patch, int strip,
 		break;
 	case 2: /* an orig and a diff/.ref */
 		f = fopen(argv[1], "r");
+		check_dir(argv[1], fileno(f));
 		if (!f) {
 			fprintf(stderr, "%s: cannot open %s\n", Cmd, argv[0]);
 			exit(1);
diff --git a/wiggle.c b/wiggle.c
index 39907a9..ad89929 100644
--- a/wiggle.c
+++ b/wiggle.c
@@ -89,17 +89,30 @@
 #include	<stdlib.h>
 #include	<stdio.h>
 #include	<ctype.h>
+#include	<sys/stat.h>
 
 char *Cmd = "wiggle";
 int do_trace = 0;
 
-void die()
+void die(char *reason)
 {
-	fprintf(stderr, "%s: fatal error\n", Cmd);
-	abort();
+	fprintf(stderr, "%s: fatal error: %s failure\n", Cmd, reason);
 	exit(3);
 }
 
+void check_dir(char *name, int fd)
+{
+	struct stat st;
+	if (fstat(fd, &st) != 0) {
+		fprintf(stderr, "%s: fatal: %s is strange\n", Cmd, name);
+		exit(3);
+	}
+	if (S_ISDIR(st.st_mode)) {
+		fprintf(stderr, "%s: %s is a directory\n", Cmd, name);
+		exit(3);
+	}
+}
+
 void *xmalloc(int size)
 {
 	void *rv = malloc(size);
@@ -612,6 +625,7 @@ static int multi_merge(int argc, char *argv[], int obj, int blanks,
 			Cmd, filename);
 		return 2;
 	}
+	check_dir(filename, fileno(f));
 	pl = parse_patch(f, NULL, &num_patches);
 	fclose(f);
 	if (set_prefix(pl, num_patches, strip) == 0) {
diff --git a/wiggle.h b/wiggle.h
index 1a7afb9..87f4c4d 100644
--- a/wiggle.h
+++ b/wiggle.h
@@ -177,7 +177,8 @@ extern struct ci make_merger(struct file a, struct file b, struct file c,
 			     struct csl *c1, struct csl *c2, int words,
 			     int ignore_already, int show_wiggles);
 
-extern void die(void);
+extern void die(char *reason);
+extern void check_dir(char *name, int fd);
 extern void *xmalloc(int len);
 extern int do_trace;