[PATCH] Fix access to uninitialized variable in fill_in_stop_func

[Pedro Franco de Carvalho <pedromfc@linux.ibm.com>]

This patch changes fill_in_stop_func to check the return value of
find_pc_partial_function before accessing the block pointer that is only
written by find_pc_partial_function if it returns a success status.

gdb/ChangeLog:
YYYY-MM-DD  Pedro Franco de Carvalho  <pedromfc@linux.ibm.com>

	* infrun.c (fill_in_stop_func): Use return value of
	find_pc_partial_function, remove comment.
---
 gdb/infrun.c | 15 +++++++--------
 1 file changed, 7 insertions(+), 8 deletions(-)

diff --git a/gdb/infrun.c b/gdb/infrun.c
index a9588f896a..15c778c7f3 100644
--- a/gdb/infrun.c
+++ b/gdb/infrun.c
@@ -4117,13 +4117,12 @@ fill_in_stop_func (struct gdbarch *gdbarch,
     {
       const block *block;
 
-      /* Don't care about return value; stop_func_start and stop_func_name
-	 will both be 0 if it doesn't work.  */
-      find_pc_partial_function (ecs->event_thread->suspend.stop_pc,
-				&ecs->stop_func_name,
-				&ecs->stop_func_start,
-				&ecs->stop_func_end,
-				&block);
+      bool status = (find_pc_partial_function
+		     (ecs->event_thread->suspend.stop_pc,
+		      &ecs->stop_func_name,
+		      &ecs->stop_func_start,
+		      &ecs->stop_func_end,
+		      &block));
 
       /* The call to find_pc_partial_function, above, will set
 	 stop_func_start and stop_func_end to the start and end
@@ -4133,7 +4132,7 @@ fill_in_stop_func (struct gdbarch *gdbarch,
 	 the function's start offset and entrypoint.  Note that
 	 stop_func_start is NOT advanced when in a range of a
 	 non-contiguous block that does not contain the entry pc.  */
-      if (block != nullptr
+      if (status && block != nullptr
 	  && ecs->stop_func_start <= BLOCK_ENTRY_PC (block)
 	  && BLOCK_ENTRY_PC (block) < ecs->stop_func_end)
 	{
-- 
2.20.1