[Mesa-stable] [PATCH] mesa: fix empty program log length

[Tapani Pälli]

In case we have empty log (""), we should return 0. This fixes
Khronos WebGL conformance test 'program-infolog'.

>From OpenGL ES 3.1 (and OpenGL 4.5 Core) spec:
   "If pname is INFO_LOG_LENGTH , the length of the info log, including
    a null terminator, is returned. If there is no info log, zero is
    returned."

v2: apply same fix for get_shaderiv and _mesa_GetProgramPipelineiv (Ian)

Signed-off-by: Tapani Pälli <tapani.palli at intel.com>
Reviewed-by: Iago Toral Quiroga <itoral at igalia.com> (v1)
Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=97321
Cc: "13.0" <mesa-stable at lists.freedesktop.org>
---

Simple fix for now and can be refactored later ..

 src/mesa/main/pipelineobj.c | 3 ++-
 src/mesa/main/shaderapi.c   | 6 ++++--
 2 files changed, 6 insertions(+), 3 deletions(-)

diff --git a/src/mesa/main/pipelineobj.c b/src/mesa/main/pipelineobj.c
index 8229840..310b745 100644
--- a/src/mesa/main/pipelineobj.c
+++ b/src/mesa/main/pipelineobj.c
@@ -645,7 +645,8 @@ _mesa_GetProgramPipelineiv(GLuint pipeline, GLenum pname, GLint *params)
       *params = pipe->ActiveProgram ? pipe->ActiveProgram->Name : 0;
       return;
    case GL_INFO_LOG_LENGTH:
-      *params = pipe->InfoLog ? strlen(pipe->InfoLog) + 1 : 0;
+      *params = (pipe->InfoLog && pipe->InfoLog[0] != '\0') ?
+         strlen(pipe->InfoLog) + 1 : 0;
       return;
    case GL_VALIDATE_STATUS:
       *params = pipe->Validated;
diff --git a/src/mesa/main/shaderapi.c b/src/mesa/main/shaderapi.c
index 5db4137..86fb785 100644
--- a/src/mesa/main/shaderapi.c
+++ b/src/mesa/main/shaderapi.c
@@ -654,7 +654,8 @@ get_programiv(struct gl_context *ctx, GLuint program, GLenum pname,
       *params = shProg->Validated;
       return;
    case GL_INFO_LOG_LENGTH:
-      *params = shProg->InfoLog ? strlen(shProg->InfoLog) + 1 : 0;
+      *params = (shProg->InfoLog && shProg->InfoLog[0] != '\0') ?
+         strlen(shProg->InfoLog) + 1 : 0;
       return;
    case GL_ATTACHED_SHADERS:
       *params = shProg->NumShaders;
@@ -902,7 +903,8 @@ get_shaderiv(struct gl_context *ctx, GLuint name, GLenum pname, GLint *params)
       *params = shader->CompileStatus;
       break;
    case GL_INFO_LOG_LENGTH:
-      *params = shader->InfoLog ? strlen(shader->InfoLog) + 1 : 0;
+      *params = (shader->InfoLog && shader->InfoLog[0] != '\0') ?
+         strlen(shader->InfoLog) + 1 : 0;
       break;
    case GL_SHADER_SOURCE_LENGTH:
       *params = shader->Source ? strlen((char *) shader->Source) + 1 : 0;
-- 
2.7.4