From 8d594727cc24b1d4c818c22ff751a825ff7bf4f0 Mon Sep 17 00:00:00 2001
From: human <human@neet.fi>
Date: Tue, 15 Jan 2019 11:48:34 +0200
Subject: [PATCH] lib/util.c: improve error handling in
 xbps_binpkg_{arch,pkgver}

they no longer assert or segfault on malformed strings

Closes: #48 [via git-merge-pr]
---
 lib/util.c | 27 ++++++++++++++++++++-------
 1 file changed, 20 insertions(+), 7 deletions(-)

diff --git a/lib/util.c b/lib/util.c
index 6c3b1381..57e7dede 100644
--- a/lib/util.c
+++ b/lib/util.c
@@ -118,13 +118,18 @@ xbps_binpkg_pkgver(const char *pkg)
 		fname = pkg;
 
 	/* 5 == .xbps */
-	len = strlen(fname) - 5;
+	if ((len = strlen(fname)) < 5)
+		return NULL;
+	len -= 5;
+
 	p = malloc(len+1);
 	assert(p);
 	(void)memcpy(p, fname, len);
 	p[len] = '\0';
-	p1 = strrchr(p, '.');
-	assert(p1);
+	if (!(p1 = strrchr(p, '.'))) {
+		free(p);
+		return NULL;
+	}
 	p[strlen(p)-strlen(p1)] = '\0';
 
 	/* sanity check it's a proper pkgver string */
@@ -134,6 +139,7 @@ xbps_binpkg_pkgver(const char *pkg)
 	}
 	res = strdup(p);
 	assert(res);
+
 	free(p);
 	return res;
 }
@@ -152,14 +158,21 @@ xbps_binpkg_arch(const char *pkg)
 		fname = pkg;
 
 	/* 5 == .xbps */
-	len = strlen(fname) - 5;
+	if ((len = strlen(fname)) < 5)
+		return NULL;
+	len -= 5;
+
 	p = malloc(len+1);
 	assert(p);
 	(void)memcpy(p, fname, len);
 	p[len] = '\0';
-	p1 = strrchr(p, '.') + 1;
-	assert(p1);
-	res = strdup(p1);
+	if (!(p1 = strrchr(p, '.'))) {
+		free(p);
+		return NULL;
+	}
+	res = strdup(p1 + 1);
+	assert(res);
+
 	free(p);
 	return res;
 }