[PATCH v2 1/1] opengl32: Skip filter_extensions_index() on GL contexts < 3.0.

[Matteo Bruni]

From: Matteo Bruni

glGetStringi() is not available before 3.0. We can't trust its
function pointer being NULL since the GL implementation is allowed to
return anything in this case (*cough* macOS's GL on Metal *cough*).

This probably regressed when fd92954df8cf12c61e08c7ef7acf172efb7c44ad
removed the "if (!disabled[0]) return FALSE;" exit from
filter_extensions(), although that simply exposed an existing issue.
---
 dlls/opengl32/unix_wgl.c | 44 +++++++++++++++++++++++-----------------
 1 file changed, 25 insertions(+), 19 deletions(-)

diff --git a/dlls/opengl32/unix_wgl.c b/dlls/opengl32/unix_wgl.c
index 5da69196548..e03bbc0a9c0 100644
--- a/dlls/opengl32/unix_wgl.c
+++ b/dlls/opengl32/unix_wgl.c
@@ -198,13 +198,32 @@ static GLubyte *filter_extensions_list( const char *extensions, const char *disa
     return (GLubyte *)str;
 }

+static const char *parse_gl_version( const char *gl_version, int *major, int *minor )
+{
+    const char *ptr = gl_version;
+
+    *major = atoi( ptr );
+    if (*major <= 0)
+        ERR( "Invalid OpenGL major version %d.\n", *major );
+
+    while (isdigit( *ptr )) ++ptr;
+    if (*ptr++ != '.')
+        ERR( "Invalid OpenGL version string %s.\n", debugstr_a(gl_version) );
+
+    *minor = atoi( ptr );
+
+    while (isdigit( *ptr )) ++ptr;
+    return ptr;
+}
+
 static GLuint *filter_extensions_index( TEB *teb, const char *disabled )
 {
     const struct opengl_funcs *funcs = teb->glTable;
+    const char *ext, *version;
     GLuint *disabled_index;
     GLint extensions_count;
     unsigned int i = 0, j;
-    const char *ext;
+    int major, minor;

if (!funcs->ext.p_glGetStringi)
     {
@@ -213,6 +232,11 @@ static GLuint *filter_extensions_index( TEB *teb, const char *disabled )
         if (!funcs->ext.p_glGetStringi) return NULL;
     }

+    version = (const char *)funcs->gl.p_glGetString( GL_VERSION );
+    parse_gl_version( version, &major, &minor );
+    if (major < 3)
+        return NULL;
+
     funcs->gl.p_glGetIntegerv( GL_NUM_EXTENSIONS, &extensions_count );
     disabled_index = malloc( extensions_count * sizeof(*disabled_index) );
     if (!disabled_index) return NULL;
@@ -413,24 +437,6 @@ static BOOL check_extension_support( TEB *teb, const char *extension, const char
     return FALSE;
 }

-static const char *parse_gl_version( const char *gl_version, int *major, int *minor )
-{
-    const char *ptr = gl_version;
-
-    *major = atoi( ptr );
-    if (*major <= 0)
-        ERR( "Invalid OpenGL major version %d.\n", *major );
-
-    while (isdigit( *ptr )) ++ptr;
-    if (*ptr++ != '.')
-        ERR( "Invalid OpenGL version string %s.\n", debugstr_a(gl_version) );
-
-    *minor = atoi( ptr );
-
-    while (isdigit( *ptr )) ++ptr;
-    return ptr;
-}
-
 static void wrap_glGetIntegerv( TEB *teb, GLenum pname, GLint *data )
 {
     const struct opengl_funcs *funcs = teb->glTable;