Safely handle escape sequences

And accompanying tests

lib/strbuf.c

@@ -68,6 +68,7 @@ void strbuf_append_char(strbuf_t *buf, char c)
   strbuf_ensure_capacity(buf, 1);
   *(buf->string + buf->length) = c;
   ++(buf->length);
+  *(buf->string + buf->length) = '\0';
 }
 
 /* ------------------------------------------------------------------------- */

tests/testdata/strings.cfg

+escape_seqs:
+{
+  str = "abc";
+  newline = "abc\ndef\n";
+  cr = "abc\rdef\r";
+  tab = "abc\tdef\t";
+  feed = "abc\fdef\f";
+  backslash = "abc\\def\\";
+  dquote = "abc\"def\"";
+};

tests/tests.c

@@ -437,6 +437,57 @@ TT_TEST(RemoveSetting)
 
 /* ------------------------------------------------------------------------- */
 
+TT_TEST(EscapedStrings)
+{
+  config_t cfg;
+  config_setting_t* rc;
+  int ok;
+  const char* str;
+
+  config_init(&cfg);
+  config_set_include_dir(&cfg, "./testdata");
+
+  ok = config_read_file(&cfg, "testdata/strings.cfg");
+  if(!ok)
+  {
+    printf("error: %s:%d\n", config_error_text(&cfg),
+           config_error_line(&cfg));
+  }
+  TT_ASSERT_TRUE(ok);
+
+  ok = config_lookup_string(&cfg, "escape_seqs.str", &str);
+  TT_ASSERT_TRUE(ok);
+  TT_ASSERT_STR_EQ("abc", str);
+
+  ok = config_lookup_string(&cfg, "escape_seqs.newline", &str);
+  TT_ASSERT_TRUE(ok);
+  TT_ASSERT_STR_EQ("abc\ndef\n", str);
+
+  ok = config_lookup_string(&cfg, "escape_seqs.cr", &str);
+  TT_ASSERT_TRUE(ok);
+  TT_ASSERT_STR_EQ("abc\rdef\r", str);
+
+  ok = config_lookup_string(&cfg, "escape_seqs.tab", &str);
+  TT_ASSERT_TRUE(ok);
+  TT_ASSERT_STR_EQ("abc\tdef\t", str);
+
+  ok = config_lookup_string(&cfg, "escape_seqs.feed", &str);
+  TT_ASSERT_TRUE(ok);
+  TT_ASSERT_STR_EQ("abc\fdef\f", str);
+
+  ok = config_lookup_string(&cfg, "escape_seqs.backslash", &str);
+  TT_ASSERT_TRUE(ok);
+  TT_ASSERT_STR_EQ("abc\\def\\", str);
+
+  ok = config_lookup_string(&cfg, "escape_seqs.dquote", &str);
+  TT_ASSERT_TRUE(ok);
+  TT_ASSERT_STR_EQ("abc\"def\"", str);
+
+  config_destroy(&cfg);
+}
+
+/* ------------------------------------------------------------------------- */
+
 int main(int argc, char **argv)
 {
   int failures;
@@ -453,6 +504,7 @@ int main(int argc, char **argv)
   TT_SUITE_TEST(LibConfigTests, BigInt6);
   TT_SUITE_TEST(LibConfigTests, BigInt7);
   TT_SUITE_TEST(LibConfigTests, RemoveSetting);
+  TT_SUITE_TEST(LibConfigTests, EscapedStrings);
   TT_SUITE_RUN(LibConfigTests);
   failures = TT_SUITE_NUM_FAILURES(LibConfigTests);
   TT_SUITE_END(LibConfigTests);