From: Theodore Ts'o <tytso@mit.edu>
Date: Sun, 12 Nov 2006 22:43:50 +0000 (-0500)
Subject: Avoid infinite substitution loop in subst caused by autoconf pre-v2.60
X-Git-Tag: E2FSPROGS-1_40-WIP-1114~14
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=98224fbc1db8387da1fe0fd1bb3be25c18be2e98;p=thirdparty%2Fe2fsprogs.git

Avoid infinite substitution loop in subst caused by autoconf pre-v2.60

Autoconf versions before 2.60 don't have datarootdir defined, and so this
resulted in a @datarootdir@ --> @datarootdir@ infinite expansion.

Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
---

diff --git a/util/ChangeLog b/util/ChangeLog
index b9ca5c5fc..5f8f89a41 100644
--- a/util/ChangeLog
+++ b/util/ChangeLog
@@ -1,3 +1,10 @@
+2006-11-12  Theodore Tso  <tytso@mit.edu>
+
+	* subst.c (substitute_line): Avoid infinite loop caused by a
+		substition such as @datarootdir@ --> @datarootdir@.  (This
+		was caused by autoconf versions before 2.60, which didn't
+		define the @datarootdir@ expansion.
+
 2006-10-22  Theodore Tso  <tytso@mit.edu>
 
 	* subst.conf.in: Add datarootdir definition for compatibility with
diff --git a/util/subst.c b/util/subst.c
index 9244e6203..445d3186a 100644
--- a/util/subst.c
+++ b/util/subst.c
@@ -165,6 +165,12 @@ static void substitute_line(char *line)
 #endif
 		ptr = name_ptr-1;
 		replace_string(ptr, end_ptr, ent->value);
+		if ((ent->value[0] == '@') &&
+		    (strlen(replace_name) == strlen(ent->value)-2) &&
+		    !strncmp(replace_name, ent->value+1, 
+			     strlen(ent->value)-2))
+			/* avoid an infinite loop */
+			ptr += strlen(ent->value);
 	}
 	/*
 	 * Now do a second pass to expand ${FOO}