From a05e039ccec6e7140ba2e28ab035a25ed8fa3b34 Mon Sep 17 00:00:00 2001
From: Juan RP <xtraeme@gmail.com>
Date: Thu, 19 Feb 2015 11:11:58 +0100
Subject: [PATCH] Revert "Stop converting relative symlinks to absolute."

This reverts commit 9ae3638429f253c5947bfb57129338122e77fa51.

This change is ok, but cannot be used right now because all existing
binpkgs were created with an old xbps-create(8).
---
 NEWS                                 |  4 +--
 bin/xbps-create/main.c               | 48 ++++++++++++++++++++++++++--
 bin/xbps-pkgdb/check_pkg_symlinks.c  |  2 +-
 include/xbps.h.in                    | 13 +++++---
 lib/package_remove.c                 |  2 +-
 lib/util.c                           | 48 ++++++++++++++++++++++++++--
 tests/xbps/xbps-create/basic_test.sh |  8 ++---
 7 files changed, 105 insertions(+), 20 deletions(-)

diff --git a/NEWS b/NEWS
index 3c9bb542..eb28c263 100644
--- a/NEWS
+++ b/NEWS
@@ -3,9 +3,7 @@ xbps-0.44 (???):
  * xbps-pkgdb(8): this now uses the code from libxbps to check the target file
    of symlinks. This fixes some false positives with symlinks.
 
- * xbps-create(8): relative target file of symlinks aren't converted to absolute
-   anymore. This just stores what the symlink points to, does not matter if
-   it's relative or absolute path.
+ * xbps-create(8): properly detect target of relative symlinks in some cases.
 
  * libxbps: make sure that symlinks with relative target are detected and removed
    properly. Fix #78: https://github.com/voidlinux/xbps/issues/78
diff --git a/bin/xbps-create/main.c b/bin/xbps-create/main.c
index 8c47bc64..e089700d 100644
--- a/bin/xbps-create/main.c
+++ b/bin/xbps-create/main.c
@@ -1,5 +1,5 @@
 /*-
- * Copyright (c) 2012-2015 Juan Romero Pardines.
+ * Copyright (c) 2012-2014 Juan Romero Pardines.
  * All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
@@ -234,6 +234,8 @@ ftw_cb(const char *fpath, const struct stat *sb, int type, struct FTW *ftwbuf _u
 {
 	struct xentry *xe = NULL;
 	const char *filep = NULL;
+	char *buf, *p, *p2, *dname;
+	ssize_t r;
 
 	/* Ignore metadata files generated by xbps-src and destdir */
 	if ((strcmp(fpath, ".") == 0) ||
@@ -270,10 +272,50 @@ ftw_cb(const char *fpath, const struct stat *sb, int type, struct FTW *ftwbuf _u
 		 */
 		xe->type = strdup("links");
 		assert(xe->type);
-		xe->target = xbps_symlink_target(fpath);
-		if (xe->target == NULL)
+		buf = malloc(sb->st_size+1);
+		assert(buf);
+		r = readlink(fpath, buf, sb->st_size+1);
+		if (r < 0 || r > sb->st_size)
 			die("failed to process symlink %s:", fpath);
 
+		buf[sb->st_size] = '\0';
+		/*
+		 * Check if symlink is absolute or relative; on the former
+		 * make it absolute for the target object.
+		 */
+		if (strstr(buf, "./")) {
+			p = realpath(fpath, NULL);
+			if (p == NULL) {
+				/*
+				 * This symlink points to an unexistent file,
+				 * which might be provided in another package.
+				 * So let's use the same target.
+				 */
+				xe->target = strdup(buf);
+			} else {
+				/*
+				 * Sanitize destdir just in case.
+				 */
+				if ((p2 = realpath(destdir, NULL)) == NULL)
+					die("failed to sanitize destdir %s: %s", destdir, strerror(errno));
+
+				xe->target = strdup(p+strlen(p2));
+				free(p2);
+				free(p);
+			}
+		} else if (buf[0] != '/') {
+			/* relative path */
+			p = strdup(filep);
+			assert(p);
+			dname = dirname(p);
+			assert(dname);
+			xe->target = xbps_xasprintf("%s/%s", dname, buf);
+			free(p);
+		} else {
+			xe->target = strdup(buf);
+		}
+		assert(xe->target);
+		free(buf);
 	} else if (type == FTW_F) {
 		struct xentry *xep;
 		bool hlink = false;
diff --git a/bin/xbps-pkgdb/check_pkg_symlinks.c b/bin/xbps-pkgdb/check_pkg_symlinks.c
index 94c758d4..1bbbad93 100644
--- a/bin/xbps-pkgdb/check_pkg_symlinks.c
+++ b/bin/xbps-pkgdb/check_pkg_symlinks.c
@@ -77,7 +77,7 @@ check_pkg_symlinks(struct xbps_handle *xhp, const char *pkgname, void *arg)
 			continue;
 		}
 		snprintf(path, sizeof(path), "%s/%s", xhp->rootdir, file);
-		if ((lnk = xbps_symlink_target(path)) == NULL) {
+		if ((lnk = xbps_symlink_target(xhp, path, tgt)) == NULL) {
 			xbps_error_printf("%s: broken symlink %s (target: %s)\n", pkgname, file, tgt);
 			broken = true;
 			continue;
diff --git a/include/xbps.h.in b/include/xbps.h.in
index 12775a47..23dea55b 100644
--- a/include/xbps.h.in
+++ b/include/xbps.h.in
@@ -48,7 +48,7 @@
  *
  * This header documents the full API for the XBPS Library.
  */
-#define XBPS_API_VERSION	"20150219-2"
+#define XBPS_API_VERSION	"20150219-1"
 
 #ifndef XBPS_VERSION
  #define XBPS_VERSION		"UNSET"
@@ -1945,14 +1945,17 @@ char *xbps_pubkey2fp(struct xbps_handle *xhp, xbps_data_t pubkey);
 char *xbps_sanitize_path(const char *src);
 
 /**
- * Returns the target file of the symlink \a symlink.
+ * Returns a sanitized target file of \a path without the rootdir component.
  *
- * @param[in] symlink The path to a symlink.
+ * @param[in] xhp The pointer to an xbps_handle struct.
+ * @param[in] path path component.
+ * @param[in] target The stored target file of a symlink.
  *
- * @return The target file in a buffer.
+ * @return The sanitized path in a buffer.
  * The returned buffer must be free(3)d when it's no longer necessary.
  */
-char *xbps_symlink_target(const char *symlink);
+char *xbps_symlink_target(struct xbps_handle *xhp, const char *path,
+		const char *target);
 
 /*@}*/
 
diff --git a/lib/package_remove.c b/lib/package_remove.c
index 4fdfc6f2..fff1c9d3 100644
--- a/lib/package_remove.c
+++ b/lib/package_remove.c
@@ -213,7 +213,7 @@ remove_pkg_files(struct xbps_handle *xhp,
 
 			xbps_dictionary_get_cstring_nocopy(obj, "target", &target);
 			assert(target);
-			lnk = xbps_symlink_target(path);
+			lnk = xbps_symlink_target(xhp, path, target);
 			if (lnk == NULL) {
 				xbps_dbg_printf(xhp, "[remove] %s "
 				    "symlink_target: %s\n", path, strerror(errno));
diff --git a/lib/util.c b/lib/util.c
index e9f84324..066d0a7c 100644
--- a/lib/util.c
+++ b/lib/util.c
@@ -454,10 +454,10 @@ xbps_sanitize_path(const char *src)
 }
 
 char *
-xbps_symlink_target(const char *path)
+xbps_symlink_target(struct xbps_handle *xhp, const char *path, const char *tgt)
 {
 	struct stat sb;
-	char *lnk = NULL;
+	char *p, *p1, *dname, *res = NULL, *lnk = NULL;
 	ssize_t r;
 
 	if (lstat(path, &sb) == -1)
@@ -472,5 +472,47 @@ xbps_symlink_target(const char *path)
 		return NULL;
 	}
 	lnk[sb.st_size] = '\0';
-	return lnk;
+
+	if (tgt[0] != '/') {
+		/*
+		 * target file is relative and wasn't converted to absolute by
+		 * xbps-create(8), just compare it as is.
+		 */
+		return lnk;
+	}
+
+	if (strstr(lnk, "./") || lnk[0] != '/') {
+		/* relative */
+		p = strdup(path);
+		assert(p);
+		dname = dirname(p);
+		assert(dname);
+		p = xbps_xasprintf("%s/%s", dname, lnk);
+		assert(p);
+		p1 = xbps_sanitize_path(p);
+		assert(p1);
+		free(p);
+		if ((strstr(p1, "./")) && (p = realpath(p1, NULL))) {
+			if (strcmp(xhp->rootdir, "/") == 0)
+				res = strdup(p);
+			else
+				res = strdup(p + strlen(xhp->rootdir));
+
+			free(p);
+		}
+		if (res == NULL) {
+			if (strcmp(xhp->rootdir, "/") == 0)
+				res = strdup(p1);
+			else
+				res = strdup(p1 + strlen(xhp->rootdir));
+		}
+		assert(res);
+		free(lnk);
+		free(p1);
+	} else {
+		/* absolute */
+		res = lnk;
+	}
+
+	return res;
 }
diff --git a/tests/xbps/xbps-create/basic_test.sh b/tests/xbps/xbps-create/basic_test.sh
index 493d6e24..34600889 100644
--- a/tests/xbps/xbps-create/basic_test.sh
+++ b/tests/xbps/xbps-create/basic_test.sh
@@ -33,7 +33,7 @@ hardlinks_size_body() {
 atf_test_case symlink_relative_target
 
 symlink_relative_target_head() {
-	atf_set "descr" "xbps-create(8): relative symlinks in destdir"
+	atf_set "descr" "xbps-create(8): relative symlinks in destdir must be absolute"
 }
 
 symlink_relative_target_body() {
@@ -48,7 +48,7 @@ symlink_relative_target_body() {
 	xbps-rindex -d -a repo/*.xbps
 	atf_check_equal $? 0
 	result="$(xbps-query -r root --repository=repo -f foo|tr -d '\n')"
-	expected="/usr/include/gsm/gsm.h/usr/include/gsm.h -> gsm/gsm.h"
+	expected="/usr/include/gsm/gsm.h/usr/include/gsm.h -> /usr/include/gsm/gsm.h"
 	rv=0
 	if [ "$result" != "$expected" ]; then
 		echo "result: $result"
@@ -61,7 +61,7 @@ symlink_relative_target_body() {
 atf_test_case symlink_relative_target_cwd
 
 symlink_relative_target_cwd_head() {
-	atf_set "descr" "xbps-create(8): relative symlinks to cwd in destdir"
+	atf_set "descr" "xbps-create(8): relative symlinks to cwd in destdir must be absolute"
 }
 
 symlink_relative_target_cwd_body() {
@@ -76,7 +76,7 @@ symlink_relative_target_cwd_body() {
 	xbps-rindex -d -a repo/*.xbps
 	atf_check_equal $? 0
 	result="$(xbps-query -r root --repository=repo -f foo|tr -d '\n')"
-	expected="/usr/include/gsm/gsm.h/usr/include/gsm.h -> ./gsm/gsm.h"
+	expected="/usr/include/gsm/gsm.h/usr/include/gsm.h -> /usr/include/gsm/gsm.h"
 	rv=0
 	if [ "$result" != "$expected" ]; then
 		echo "result: $result"