find: fix -exec to work like stock find does.
diff --git a/findutils/find.c b/findutils/find.c
index 8618f3a..7869840 100644
--- a/findutils/find.c
+++ b/findutils/find.c
@@ -10,55 +10,108 @@
  * Licensed under the GPL version 2, see the file LICENSE in this tarball.
  */
 
+/* findutils-4.1.20:
+ *
+ * # find file.txt -exec 'echo {}' '{}  {}' ';'
+ * find: echo file.txt: No such file or directory
+ * # find file.txt -exec 'echo' '{}  {}' '; '
+ * find: missing argument to `-exec'
+ * # find file.txt -exec 'echo {}' '{}  {}' ';' junk
+ * find: paths must precede expression
+ * # find file.txt -exec 'echo {}' '{}  {}' ';' junk ';'
+ * find: paths must precede expression
+ * # find file.txt -exec 'echo' '{}  {}' ';'
+ * file.txt  file.txt
+ * (strace: execve("/bin/echo", ["echo", "file.txt  file.txt"], [ 30 vars ]))
+ *
+ * bboxed find rev 16467: above - works, below - doesn't
+ *
+ * # find file.txt -exec 'echo' '{}  {}' ';' -print -exec pwd ';'
+ * file.txt  file.txt
+ * file.txt
+ * /tmp
+ */
+
 #include "busybox.h"
 #include <fnmatch.h>
 
 static char *pattern;
-#ifdef CONFIG_FEATURE_FIND_PRINT0
+#if ENABLE_FEATURE_FIND_PRINT0
 static char printsep = '\n';
 #endif
 
-#ifdef CONFIG_FEATURE_FIND_TYPE
+#if ENABLE_FEATURE_FIND_TYPE
 static int type_mask = 0;
 #endif
 
-#ifdef CONFIG_FEATURE_FIND_PERM
+#if ENABLE_FEATURE_FIND_PERM
 static char perm_char = 0;
 static int perm_mask = 0;
 #endif
 
-#ifdef CONFIG_FEATURE_FIND_MTIME
+#if ENABLE_FEATURE_FIND_MTIME
 static char mtime_char;
 static int mtime_days;
 #endif
 
-#ifdef CONFIG_FEATURE_FIND_MMIN
+#if ENABLE_FEATURE_FIND_MMIN
 static char mmin_char;
 static int mmin_mins;
 #endif
 
-#ifdef CONFIG_FEATURE_FIND_XDEV
+#if ENABLE_FEATURE_FIND_XDEV
 static dev_t *xdev_dev;
 static int xdev_count = 0;
 #endif
 
-#ifdef CONFIG_FEATURE_FIND_NEWER
+#if ENABLE_FEATURE_FIND_NEWER
 static time_t newer_mtime;
 #endif
 
-#ifdef CONFIG_FEATURE_FIND_INUM
+#if ENABLE_FEATURE_FIND_INUM
 static ino_t inode_num;
 #endif
 
-#ifdef CONFIG_FEATURE_FIND_EXEC
-static char **exec_str;
-static int num_matches;
-static int exec_opt;
+#if ENABLE_FEATURE_FIND_EXEC
+static char **exec_argv;
+static int *subst_count;
+static int exec_argc;
 #endif
 
+static int count_subst(const char *str)
+{
+	int count = 0;
+	while ((str = strstr(str, "{}"))) {
+		count++;
+		str++;
+	}
+	return count;
+}
+
+
+static char* subst(const char *src, int count, const char* filename)
+{
+	char *buf, *dst, *end;
+	int flen = strlen(filename);
+//puts(src);
+	/* we replace each '{}' with filename: growth by strlen-2 */
+	buf = dst = xmalloc(strlen(src) + count*(flen-2) + 1);
+	while ((end = strstr(src, "{}"))) {
+		memcpy(dst, src, end - src);
+		dst += end - src;
+		src = end + 2;
+		memcpy(dst, filename, flen);
+		dst += flen;
+	}
+	strcpy(dst, src);
+//puts(buf);
+	return buf;
+}
+
+
 static int fileAction(const char *fileName, struct stat *statbuf, void* junk, int depth)
 {
-#ifdef CONFIG_FEATURE_FIND_XDEV
+#if ENABLE_FEATURE_FIND_XDEV
 	if (S_ISDIR(statbuf->st_mode) && xdev_count) {
 		int i;
 		for (i=0; i<xdev_count; i++) {
@@ -77,13 +130,13 @@
 		if (fnmatch(pattern, tmp, FNM_PERIOD) != 0)
 			goto no_match;
 	}
-#ifdef CONFIG_FEATURE_FIND_TYPE
+#if ENABLE_FEATURE_FIND_TYPE
 	if (type_mask != 0) {
 		if (!((statbuf->st_mode & S_IFMT) == type_mask))
 			goto no_match;
 	}
 #endif
-#ifdef CONFIG_FEATURE_FIND_PERM
+#if ENABLE_FEATURE_FIND_PERM
 	if (perm_mask != 0) {
 		if (!((isdigit(perm_char) && (statbuf->st_mode & 07777) == perm_mask) ||
 			 (perm_char == '-' && (statbuf->st_mode & perm_mask) == perm_mask) ||
@@ -91,7 +144,7 @@
 			goto no_match;
 	}
 #endif
-#ifdef CONFIG_FEATURE_FIND_MTIME
+#if ENABLE_FEATURE_FIND_MTIME
 	if (mtime_char != 0) {
 		time_t file_age = time(NULL) - statbuf->st_mtime;
 		time_t mtime_secs = mtime_days * 24 * 60 * 60;
@@ -102,7 +155,7 @@
 			goto no_match;
 	}
 #endif
-#ifdef CONFIG_FEATURE_FIND_MMIN
+#if ENABLE_FEATURE_FIND_MMIN
 	if (mmin_char != 0) {
 		time_t file_age = time(NULL) - statbuf->st_mtime;
 		time_t mmin_secs = mmin_mins * 60;
@@ -113,32 +166,37 @@
 			goto no_match;
 	}
 #endif
-#ifdef CONFIG_FEATURE_FIND_NEWER
+#if ENABLE_FEATURE_FIND_NEWER
 	if (newer_mtime != 0) {
 		time_t file_age = newer_mtime - statbuf->st_mtime;
 		if (file_age >= 0)
 			goto no_match;
 	}
 #endif
-#ifdef CONFIG_FEATURE_FIND_INUM
+#if ENABLE_FEATURE_FIND_INUM
 	if (inode_num != 0) {
 		if (!(statbuf->st_ino == inode_num))
 			goto no_match;
 	}
 #endif
-#ifdef CONFIG_FEATURE_FIND_EXEC
-	if (exec_opt) {
+#if ENABLE_FEATURE_FIND_EXEC
+	if (exec_argc) {
 		int i;
-		char *cmd_string = "";
-		for (i = 0; i < num_matches; i++)
-			cmd_string = xasprintf("%s%s%s", cmd_string, exec_str[i], fileName);
-		cmd_string = xasprintf("%s%s", cmd_string, exec_str[num_matches]);
-		system(cmd_string);
+		char *argv[exec_argc+1];
+		for (i = 0; i < exec_argc; i++)
+			argv[i] = subst(exec_argv[i], subst_count[i], fileName);
+		argv[i] = NULL; /* terminate the list */
+		errno = 0;
+		wait4pid(spawn(argv));
+		if (errno)
+			bb_perror_msg("%s", argv[0]);
+		for (i = 0; i < exec_argc; i++)
+			free(argv[i]);
 		goto no_match;
 	}
 #endif
 
-#ifdef CONFIG_FEATURE_FIND_PRINT0
+#if ENABLE_FEATURE_FIND_PRINT0
 	printf("%s%c", fileName, printsep);
 #else
 	puts(fileName);
@@ -147,7 +205,7 @@
 	return TRUE;
 }
 
-#ifdef CONFIG_FEATURE_FIND_TYPE
+#if ENABLE_FEATURE_FIND_TYPE
 static int find_type(char *type)
 {
 	int mask = 0;
@@ -186,7 +244,7 @@
 int find_main(int argc, char **argv)
 {
 	int dereference = FALSE;
-	int i, firstopt, status = EXIT_SUCCESS;
+	int i, j, firstopt, status = EXIT_SUCCESS;
 
 	for (firstopt = 1; firstopt < argc; firstopt++) {
 		if (argv[firstopt][0] == '-')
@@ -195,54 +253,62 @@
 
 	/* Parse any options */
 	for (i = firstopt; i < argc; i++) {
-		if (strcmp(argv[i], "-follow") == 0)
+		char *arg = argv[i];
+		char *arg1 = argv[i+1];
+		if (strcmp(arg, "-follow") == 0)
 			dereference = TRUE;
-		else if (strcmp(argv[i], "-print") == 0) {
+		else if (strcmp(arg, "-print") == 0) {
 			;
-			}
-#ifdef CONFIG_FEATURE_FIND_PRINT0
-		else if (strcmp(argv[i], "-print0") == 0)
+		}
+#if ENABLE_FEATURE_FIND_PRINT0
+		else if (strcmp(arg, "-print0") == 0)
 			printsep = '\0';
 #endif
-		else if (strcmp(argv[i], "-name") == 0) {
+		else if (strcmp(arg, "-name") == 0) {
 			if (++i == argc)
-				bb_error_msg_and_die(bb_msg_requires_arg, "-name");
-			pattern = argv[i];
-#ifdef CONFIG_FEATURE_FIND_TYPE
-		} else if (strcmp(argv[i], "-type") == 0) {
+				bb_error_msg_and_die(bb_msg_requires_arg, arg);
+			pattern = arg1;
+#if ENABLE_FEATURE_FIND_TYPE
+		} else if (strcmp(arg, "-type") == 0) {
 			if (++i == argc)
-				bb_error_msg_and_die(bb_msg_requires_arg, "-type");
-			type_mask = find_type(argv[i]);
+				bb_error_msg_and_die(bb_msg_requires_arg, arg);
+			type_mask = find_type(arg1);
 #endif
-#ifdef CONFIG_FEATURE_FIND_PERM
-		} else if (strcmp(argv[i], "-perm") == 0) {
+#if ENABLE_FEATURE_FIND_PERM
+/* TODO:
+ * -perm mode   File's permission bits are exactly mode (octal or symbolic).
+ *              Symbolic modes use mode 0 as a point of departure.
+ * -perm -mode  All of the permission bits mode are set for the file.
+ * -perm +mode  Any of the permission bits mode are set for the file.
+ */
+		} else if (strcmp(arg, "-perm") == 0) {
 			if (++i == argc)
-				bb_error_msg_and_die(bb_msg_requires_arg, "-perm");
-			perm_mask = xstrtol_range(argv[i], 8, 0, 07777);
-			perm_char = argv[i][0];
+				bb_error_msg_and_die(bb_msg_requires_arg, arg);
+			perm_mask = xstrtol_range(arg1, 8, 0, 07777);
+			perm_char = arg1[0];
 			if (perm_char == '-')
 				perm_mask = -perm_mask;
 #endif
-#ifdef CONFIG_FEATURE_FIND_MTIME
-		} else if (strcmp(argv[i], "-mtime") == 0) {
+#if ENABLE_FEATURE_FIND_MTIME
+		} else if (strcmp(arg, "-mtime") == 0) {
 			if (++i == argc)
-				bb_error_msg_and_die(bb_msg_requires_arg, "-mtime");
-			mtime_days = xatol(argv[i]);
-			mtime_char = argv[i][0];
+				bb_error_msg_and_die(bb_msg_requires_arg, arg);
+			mtime_days = xatol(arg1);
+			mtime_char = arg1[0];
 			if (mtime_char == '-')
 				mtime_days = -mtime_days;
 #endif
-#ifdef CONFIG_FEATURE_FIND_MMIN
-		} else if (strcmp(argv[i], "-mmin") == 0) {
+#if ENABLE_FEATURE_FIND_MMIN
+		} else if (strcmp(arg, "-mmin") == 0) {
 			if (++i == argc)
-				bb_error_msg_and_die(bb_msg_requires_arg, "-mmin");
-			mmin_mins = xatol(argv[i]);
-			mmin_char = argv[i][0];
+				bb_error_msg_and_die(bb_msg_requires_arg, arg);
+			mmin_mins = xatol(arg1);
+			mmin_char = arg1[0];
 			if (mmin_char == '-')
 				mmin_mins = -mmin_mins;
 #endif
-#ifdef CONFIG_FEATURE_FIND_XDEV
-		} else if (strcmp(argv[i], "-xdev") == 0) {
+#if ENABLE_FEATURE_FIND_XDEV
+		} else if (strcmp(arg, "-xdev") == 0) {
 			struct stat stbuf;
 
 			xdev_count = (firstopt - 1) ? (firstopt - 1) : 1;
@@ -251,55 +317,46 @@
 			if (firstopt == 1) {
 				xstat(".", &stbuf);
 				xdev_dev[0] = stbuf.st_dev;
-			}
-			else {
-
-				for (i = 1; i < firstopt; i++) {
-					xstat(argv[i], &stbuf);
-					xdev_dev[i-1] = stbuf.st_dev;
+			} else {
+				for (j = 1; j < firstopt; i++) {
+					xstat(argv[j], &stbuf);
+					xdev_dev[j-1] = stbuf.st_dev;
 				}
 			}
 #endif
-#ifdef CONFIG_FEATURE_FIND_NEWER
-		} else if (strcmp(argv[i], "-newer") == 0) {
+#if ENABLE_FEATURE_FIND_NEWER
+		} else if (strcmp(arg, "-newer") == 0) {
 			struct stat stat_newer;
 			if (++i == argc)
-				bb_error_msg_and_die(bb_msg_requires_arg, "-newer");
-			xstat(argv[i], &stat_newer);
+				bb_error_msg_and_die(bb_msg_requires_arg, arg);
+			xstat(arg1, &stat_newer);
 			newer_mtime = stat_newer.st_mtime;
 #endif
-#ifdef CONFIG_FEATURE_FIND_INUM
-		} else if (strcmp(argv[i], "-inum") == 0) {
+#if ENABLE_FEATURE_FIND_INUM
+		} else if (strcmp(arg, "-inum") == 0) {
 			if (++i == argc)
-				bb_error_msg_and_die(bb_msg_requires_arg, "-inum");
-			inode_num = xatoul(argv[i]);
+				bb_error_msg_and_die(bb_msg_requires_arg, arg);
+			inode_num = xatoul(arg1);
 #endif
-#ifdef CONFIG_FEATURE_FIND_EXEC
-		} else if (strcmp(argv[i], "-exec") == 0) {
-			int b_pos;
-			char *cmd_string = "";
-
-			while (i++) {
-				if (i == argc)
-					bb_error_msg_and_die(bb_msg_requires_arg, "-exec");
-				if (*argv[i] == ';')
+#if ENABLE_FEATURE_FIND_EXEC
+		} else if (strcmp(arg, "-exec") == 0) {
+			i++; /* now: argv[i] is the first arg after -exec */
+			exec_argv = &argv[i];
+			exec_argc = i;
+			while (1) {
+				if (i == argc) /* did not see ';' till end */
+					bb_error_msg_and_die(bb_msg_requires_arg, arg);
+				if (argv[i][0] == ';' && argv[i][1] == '\0')
 					break;
-				cmd_string = xasprintf("%s %s", cmd_string, argv[i]);
+				i++;
 			}
-
-			if (*cmd_string == 0)
-				bb_error_msg_and_die(bb_msg_requires_arg, "-exec");
-			cmd_string++;
-			exec_str = xmalloc(sizeof(char *));
-
-			while ((b_pos = strstr(cmd_string, "{}") - cmd_string), (b_pos >= 0)) {
-				num_matches++;
-				exec_str = xrealloc(exec_str, (num_matches + 1) * sizeof(char *));
-				exec_str[num_matches - 1] = xstrndup(cmd_string, b_pos);
-				cmd_string += b_pos + 2;
-			}
-			exec_str[num_matches] = xstrdup(cmd_string);
-			exec_opt = 1;
+			exec_argc = i - exec_argc; /* number of --exec arguments */
+			if (exec_argc == 0)
+				bb_error_msg_and_die(bb_msg_requires_arg, arg);
+			subst_count = xmalloc(exec_argc * sizeof(int));
+			j = exec_argc;
+			while (j--)
+				subst_count[j] = count_subst(exec_argv[j]);
 #endif
 		} else
 			bb_show_usage();
@@ -311,8 +368,8 @@
 			status = EXIT_FAILURE;
 	} else {
 		for (i = 1; i < firstopt; i++) {
-			if (!recursive_action(argv[i], TRUE, dereference, FALSE, fileAction,
-						fileAction, NULL, 0))
+			if (!recursive_action(argv[i], TRUE, dereference, FALSE,
+					fileAction, fileAction, NULL, 0))
 				status = EXIT_FAILURE;
 		}
 	}