From 194998f397a092296123a258b3b8162797ac8cf5 Mon Sep 17 00:00:00 2001
From: John Kerl <kerl.john.r@gmail.com>
Date: Wed, 6 May 2015 19:49:23 -0700
Subject: [PATCH] corner-case bug fixes for put, filter, step

---
 c/dsls/filter_dsl_lexer.l | 4 ++--
 c/dsls/put_dsl_lexer.l    | 4 ++--
 c/mapping/mapper_filter.c | 4 ++++
 c/mapping/mapper_put.c    | 4 ++++
 c/mapping/mapper_step.c   | 6 +++++-
 5 files changed, 17 insertions(+), 5 deletions(-)

diff --git a/c/dsls/filter_dsl_lexer.l b/c/dsls/filter_dsl_lexer.l
index 36cce517b..581509395 100644
--- a/c/dsls/filter_dsl_lexer.l
+++ b/c/dsls/filter_dsl_lexer.l
@@ -78,7 +78,7 @@
 	return FILTER_DSL_NOT;
 }
 
-\$[a-zA-Z_0-9]* {
+\$[a-zA-Z_0-9]+ {
 	// Note: the parser depends on the dollar sign being here. If this is changed,
 	// that needs to be changed as well.
 	*yyextra = mlr_dsl_ast_node_alloc(yytext, MLR_DSL_AST_NODE_TYPE_FIELD_NAME);
@@ -125,7 +125,7 @@
 	return FILTER_DSL_RPAREN;
 }
 
-[a-zA-Z_][a-zA-Z_0-9]* {
+[a-zA-Z_][a-zA-Z_0-9]+ {
 	*yyextra = mlr_dsl_ast_node_alloc(yytext, MLR_DSL_AST_NODE_TYPE_FUNCTION_NAME);
 	return FILTER_DSL_FCN_NAME;
 }
diff --git a/c/dsls/put_dsl_lexer.l b/c/dsls/put_dsl_lexer.l
index c8d5344ef..cfccc5116 100644
--- a/c/dsls/put_dsl_lexer.l
+++ b/c/dsls/put_dsl_lexer.l
@@ -11,7 +11,7 @@
 %option extra-type="struct _mlr_dsl_ast_node_t **"
 
 %%
-\$[a-zA-Z_0-9]* {
+\$[a-zA-Z_0-9]+ {
 	// Note: the parser depends on the dollar sign being here. If this is changed,
 	// that needs to be changed as well.
 	*yyextra = mlr_dsl_ast_node_alloc(yytext, MLR_DSL_AST_NODE_TYPE_FIELD_NAME);
@@ -43,7 +43,7 @@
 	return PUT_DSL_CONTEXT_VARIABLE;
 }
 
-[a-zA-Z_][a-zA-Z_0-9]* {
+[a-zA-Z_][a-zA-Z_0-9]+ {
 	*yyextra = mlr_dsl_ast_node_alloc(yytext, MLR_DSL_AST_NODE_TYPE_FUNCTION_NAME);
 	return PUT_DSL_FCN_NAME;
 }
diff --git a/c/mapping/mapper_filter.c b/c/mapping/mapper_filter.c
index e0fa0d028..f5ff2b96a 100644
--- a/c/mapping/mapper_filter.c
+++ b/c/mapping/mapper_filter.c
@@ -80,6 +80,10 @@ mapper_t* mapper_filter_parse_cli(int* pargi, int argc, char** argv) {
 	mlr_dsl_expression = argv[(*pargi)++];
 
 	mlr_dsl_ast_node_holder_t* past = filter_dsl_parse(mlr_dsl_expression);
+	if (past == NULL) {
+		mapper_filter_usage(argv[0], verb);
+		return NULL;
+	}
 	if (print_asts) {
 		mlr_dsl_ast_node_print(past->proot);
 	}
diff --git a/c/mapping/mapper_put.c b/c/mapping/mapper_put.c
index d331d4efd..816a918f4 100644
--- a/c/mapping/mapper_put.c
+++ b/c/mapping/mapper_put.c
@@ -115,6 +115,10 @@ mapper_t* mapper_put_parse_cli(int* pargi, int argc, char** argv) {
 
 	// Linked list of mlr_dsl_ast_node_t*.
 	sllv_t* pasts = put_dsl_parse(mlr_dsl_expression);
+	if (pasts == NULL) {
+		mapper_put_usage(argv[0], verb);
+		return NULL;
+	}
 	if (print_asts) {
 		for (sllve_t* pe = pasts->phead; pe != NULL; pe = pe->pnext)
 			mlr_dsl_ast_node_print(pe->pvdata);
diff --git a/c/mapping/mapper_step.c b/c/mapping/mapper_step.c
index d359d543f..1a71a2bab 100644
--- a/c/mapping/mapper_step.c
+++ b/c/mapping/mapper_step.c
@@ -208,7 +208,11 @@ sllv_t* mapper_step_func(lrec_t* pinrec, context_t* pctx, void* pvstate) {
 			step_t* pstep = lhmsv_get(pmaps_level_3, step_name);
 			if (pstep == NULL) {
 				pstep = make_step(step_name, value_field_name, &pctx->statx);
-				// xxx fix me when lookup is null; and/or check at ctor time
+				if (pstep == NULL) {
+					fprintf(stderr, "mlr step: stepper \"%s\" not found.\n",
+						step_name);
+					exit(1);
+				}
 				lhmsv_put(pmaps_level_3, step_name, pstep);
 			}