From e7e3e8ee74206cd693ab57933251d4381090b20e Mon Sep 17 00:00:00 2001
From: axel <axel@liljencrantz.se>
Date: Sun, 4 Jun 2006 19:35:32 +1000
Subject: [PATCH] Add support for negative indices in arrays. Negative indices
 count from the end of an array, so -4 is the fourth index from the end

darcs-hash:20060604093532-ac50b-6e22b2f2ccfe94375fe4c32e41ccec08ca501744.gz
---
 builtin_set.c | 27 ++++++++++++++++++---------
 expand.c      |  5 +++++
 2 files changed, 23 insertions(+), 9 deletions(-)

diff --git a/builtin_set.c b/builtin_set.c
index 3db78504a..0b888f08e 100644
--- a/builtin_set.c
+++ b/builtin_set.c
@@ -177,7 +177,8 @@ static int my_env_set( const wchar_t *key, array_list_t *val, int scope )
 */
 static int parse_index( array_list_t *indexes,
 						const wchar_t *src,
-						const wchar_t *name )
+						const wchar_t *name,
+						int var_count )
 {
 	int len;
 	
@@ -224,13 +225,20 @@ static int parse_index( array_list_t *indexes,
 	{
 		wchar_t *end;
 		long l_ind = wcstol(src, &end, 10);
+		int *ind;
+		
 		if (end == src) 
 		{
 			sb_printf(sb_err, _(L"%ls: Invalid index starting at '%ls'\n"), L"set", src);
 			return 0;
 		}
+
+		if( l_ind < 0 )
+		{
+			l_ind = var_count+l_ind+1;
+		}
 		
-		int *ind = (int *) calloc(1, sizeof(int));
+		ind = (int *) calloc(1, sizeof(int));
 		*ind = (int) l_ind;
 		al_push(indexes, ind);
 		src = end;
@@ -643,13 +651,17 @@ int builtin_set( wchar_t **argv )
 		int idx_count, val_count;
 		array_list_t values;
 		array_list_t indexes;
+		array_list_t result;
 		
 		al_init(&values);
 		al_init(&indexes);
+		al_init(&result);
+
+		tokenize_variable_array( env_get(dest), &result );
 	
 		for( ; woptind<argc; woptind++ )
 		{			
-			if( !parse_index( &indexes, argv[woptind], dest ) )
+			if( !parse_index( &indexes, argv[woptind], dest, al_get_count( &result ) ) )
 			{
 				builtin_print_help( argv[0], sb_err );
 				retcode = 1;
@@ -682,10 +694,6 @@ int builtin_set( wchar_t **argv )
 			  Slice indexes have been calculated, do the actual work
 			*/
 
-			array_list_t result;
-			al_init(&result);
-
-			tokenize_variable_array( env_get(dest), &result );
 			if( erase )
 			{
 				erase_values(&result, &indexes);
@@ -712,10 +720,11 @@ int builtin_set( wchar_t **argv )
 				al_destroy( &value );
 								
 			}			
-			al_foreach( &result, (void (*)(const void *))&free );
-			al_destroy( &result );
 		}
 
+		al_foreach( &result, (void (*)(const void *))&free );
+		al_destroy( &result );
+
 		al_foreach( &indexes, (void (*)(const void *))&free );
 		al_destroy(&indexes);
 		al_destroy(&values);
diff --git a/expand.c b/expand.c
index 4180f5bd6..0b20f1f09 100644
--- a/expand.c
+++ b/expand.c
@@ -815,6 +815,11 @@ static int expand_variables( wchar_t *in, array_list_t *out, int last_idx )
 						for( j=0; j<al_get_count( var_idx_list ); j++)
 						{
 							long tmp = (long)al_get( var_idx_list, j );
+							if( tmp < 0 )
+							{
+								tmp = al_get_count( &var_item_list)+tmp+1;
+							}
+							
 							if( tmp < 1 || tmp > al_get_count( &var_item_list ) )
 							{
 								error( SYNTAX_ERROR,