From dd7af7ed6efffa5d8dea39296f77c4fa34a40020 Mon Sep 17 00:00:00 2001
From: Panu Matilainen <pmatilai@redhat.com>
Date: Fri, 11 Nov 2016 12:59:50 +0200
Subject: [PATCH 3/6] Ensure that a trigger condition actually exists.

All this time rpm has merrily accepted a trigger with no condition
at all, eg "%triggerin --". Doh. Check and error out on missing trigger.
This is all ridiculously subtle and fragile - pay attention to splitting
the line only after all error messages have been done for full error
message, but since we're now moving s further on whitespace we need
to store the separation point into another helper to avoid breaking
the other %trigger line semantics.
---
 build/parseScript.c | 13 +++++++++++--
 1 file changed, 11 insertions(+), 2 deletions(-)

diff --git a/build/parseScript.c b/build/parseScript.c
index 2cffbe4..0063422 100644
--- a/build/parseScript.c
+++ b/build/parseScript.c
@@ -15,6 +15,7 @@
 
 #include "debug.h"
 
+#define SKIPSPACE(s) { while (*(s) && risspace(*(s))) (s)++; }
 
 /**
  */
@@ -251,7 +252,7 @@ int parseScript(rpmSpec spec, int parsePart)
     if (tag == RPMTAG_TRIGGERSCRIPTS || tag == RPMTAG_FILETRIGGERSCRIPTS ||
 	tag == RPMTAG_TRANSFILETRIGGERSCRIPTS) {
 	/* break line into two at the -- separator */
-	char *s = spec->line;
+	char *sep, *s = spec->line;
 	while ((s = strstr(s, "--")) != NULL) {
 	    s += 2;
 	    if (risblank(*(s-3)) && risblank(*s))
@@ -264,7 +265,15 @@ int parseScript(rpmSpec spec, int parsePart)
 	    goto exit;
 	}
 
-	*(s-3) = '\0';
+	sep = s;
+	SKIPSPACE(s);
+	if (*s == '\0') {
+	    rpmlog(RPMLOG_ERR, _("line %d: missing trigger condition: %s\n"),
+				spec->lineNum, spec->line);
+	    goto exit;
+	}
+
+	*sep = '\0';
 	reqargs = xstrdup(s);
     }
     
-- 
2.10.2