From: Ben Hutchings <ben@decadent.org.uk>
Date: Fri, 22 Jan 2016 20:13:35 +0000 (+0000)
Subject: Fix script environment variable setting for empty lists
X-Git-Tag: debian/1.1+git20160131-1~7^2~1
X-Git-Url: https://git.decadent.org.uk/gitweb/?p=odhcp6c.git;a=commitdiff_plain;h=6326ab374ede4fff1e8019a50d4b9854b8db7625;hp=78bc7d9c835404ad1b5d2eb26de390bd45e26d2a

Fix script environment variable setting for empty lists

When setting an environment variable as a space-separated list, and
the list is empty, we must not delete the '=' before the value.

In practice putenv() is likely to discard the invalid string, leaving
the variable unset, but this is not guaranteed.

Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
---

diff --git a/src/script.c b/src/script.c
index 3579331..1533510 100644
--- a/src/script.c
+++ b/src/script.c
@@ -105,7 +105,9 @@ static void ipv6_to_env(const char *name,
 		buf_len += strlen(&buf[buf_len]);
 		buf[buf_len++] = ' ';
 	}
-	buf[buf_len - 1] = '\0';
+	if (buf[buf_len - 1] == ' ')
+		buf_len--;
+	buf[buf_len] = '\0';
 	putenv(buf);
 }
 
@@ -126,7 +128,9 @@ static void fqdn_to_env(const char *name, const uint8_t *fqdn, size_t len)
 		buf_len += strlen(&buf[buf_len]);
 		buf[buf_len++] = ' ';
 	}
-	buf[buf_len - 1] = '\0';
+	if (buf[buf_len - 1] == ' ')
+		buf_len--;
+	buf[buf_len] = '\0';
 	putenv(buf);
 }
 
@@ -201,7 +205,9 @@ static void entry_to_env(const char *name, const void *data, size_t len, enum en
 		buf[buf_len++] = ' ';
 	}
 
-	buf[buf_len - 1] = '\0';
+	if (buf[buf_len - 1] == ' ')
+		buf_len--;
+	buf[buf_len] = '\0';
 	putenv(buf);
 }
 
@@ -220,7 +226,9 @@ static void search_to_env(const char *name, const uint8_t *start, size_t len)
 		*c++ = ' ';
 	}
 
-	c[-1] = '\0';
+	if (c[-1] == ' ')
+		c--;
+	*c = '\0';
 	putenv(buf);
 }