From fc59095ff4fbef396dae30ee7bb8be381a81a058 Mon Sep 17 00:00:00 2001
From: Olly Betts <olly@survex.com>
Date: Fri, 27 Oct 2017 17:38:37 +1300
Subject: [PATCH] Deprecate allowing spaces around = in scripts

This was never documented as supported, and leads to a missing argument
quietly swallowing the next action rather than using an empty value or
giving an error.

Reported by Gaurav Arora in https://github.com/xapian/xapian/pull/182
---
 xapian-applications/omega/docs/scriptindex.rst | 11 +++++++++++
 xapian-applications/omega/omegatest            | 26 ++++++++++++++++++++++++++
 xapian-applications/omega/scriptindex.cc       | 12 ++++++++++++
 3 files changed, 49 insertions(+)

diff --git a/xapian-applications/omega/docs/scriptindex.rst b/xapian-applications/omega/docs/scriptindex.rst
index cee3bc888..20dfc9bb8 100644
--- a/xapian-applications/omega/docs/scriptindex.rst
+++ b/xapian-applications/omega/docs/scriptindex.rst
@@ -15,6 +15,17 @@ Here's an example::
  ref : field=ref boolean=Q unique=Q
  type : field=type boolean=XT
 
+Don't put spaces around the ``=`` separating an action and its argument -
+current versions allow spaces here (though this was never documented as
+supported) but it leads to a missing argument quietly swallowing the next
+action rather than using an empty value or giving an error, e.g. this takes
+``hash`` as the field name, which is unlikely to be what was intended::
+
+ url : field= hash boolean=Q unique=Q
+
+Since 1.4.6 a deprecation warning is emitted for spaces before or after the
+``=``.
+
 The actions are:
 
 boolean[=PREFIX]
diff --git a/xapian-applications/omega/omegatest b/xapian-applications/omega/omegatest
index fddd000cd..f9ba7dfb3 100755
--- a/xapian-applications/omega/omegatest
+++ b/xapian-applications/omega/omegatest
@@ -495,6 +495,32 @@ else
     failed=`expr $failed + 1`
 fi
 
+# Test we warn about spaces before and after '='.
+#
+# This has never been documented as supported, and was deprecated in 1.4.6
+# because it resulted in this quietly using hash as the field name, which is
+# probably not what was intended:
+#
+# url : field= hash boolean=Q unique=Q
+printf 'url : field= hash boolean=Q unique=Q' > "$TEST_INDEXSCRIPT"
+rm -rf "$TEST_DB"
+if $SCRIPTINDEX "$TEST_DB" "$TEST_INDEXSCRIPT" < /dev/null \
+    | grep -q "warning: putting spaces between '=' and the argument is deprecated" ; then
+    : # OK
+else
+    echo "scriptindex didn't give expected warning for space after '='"
+    failed=`expr $failed + 1`
+fi
+printf 'url : field =link' > "$TEST_INDEXSCRIPT"
+rm -rf "$TEST_DB"
+if $SCRIPTINDEX "$TEST_DB" "$TEST_INDEXSCRIPT" < /dev/null \
+    | grep -q "warning: putting spaces between the action and '=' is deprecated" ; then
+    : # OK
+else
+    echo "scriptindex didn't give expected warning for space before '='"
+    failed=`expr $failed + 1`
+fi
+
 rm "$OMEGA_CONFIG_FILE" "$TEST_INDEXSCRIPT" "$TEST_TEMPLATE"
 rm -rf "$TEST_DB"
 if [ "$failed" = 0 ] ; then
diff --git a/xapian-applications/omega/scriptindex.cc b/xapian-applications/omega/scriptindex.cc
index 1512ce510..92d21156e 100644
--- a/xapian-applications/omega/scriptindex.cc
+++ b/xapian-applications/omega/scriptindex.cc
@@ -259,9 +259,16 @@ parse_index_script(const string &filename)
 		     << ": Unknown index action '" << action << "'" << endl;
 		exit(1);
 	    }
+	    auto i_after_action = i;
 	    i = find_if(i, s.end(), [](char ch) { return !C_isspace(ch); });
 
 	    if (i != s.end() && *i == '=') {
+		if (i != i_after_action) {
+		    cout << filename << ':' << line_no
+			 << ": warning: putting spaces between the action and "
+			    "'=' is deprecated." << endl;
+		}
+
 		if (arg == NO) {
 		    cout << filename << ':' << line_no
 			 << ": Index action '" << action
@@ -270,6 +277,11 @@ parse_index_script(const string &filename)
 		}
 		++i;
 		j = find_if(i, s.end(), [](char ch) { return !C_isspace(ch); });
+		if (i != j) {
+		    cout << filename << ':' << line_no
+			 << ": warning: putting spaces between '=' and the "
+			    "argument is deprecated." << endl;
+		}
 		i = find_if(j, s.end(), [](char ch) { return C_isspace(ch); });
 		string val(j, i);
 		if (takes_integer_argument) {
-- 
2.11.4.GIT