SDL: Fixed Visual Studio warning 4701

From b078122c5301fab82a8ac99554a1bae17fb5ef96 Mon Sep 17 00:00:00 2001
From: Sam Lantinga <[EMAIL REDACTED]>
Date: Thu, 30 Mar 2023 14:02:02 -0700
Subject: [PATCH] Fixed Visual Studio warning 4701

---
 src/render/SDL_render.c      |  2 ++
 src/stdlib/SDL_string.c      | 10 ++--------
 src/video/SDL_RLEaccel.c     |  2 +-
 src/video/SDL_vulkan_utils.c |  2 +-
 4 files changed, 6 insertions(+), 10 deletions(-)

diff --git a/src/render/SDL_render.c b/src/render/SDL_render.c
index 7db0398b5fae..7437db8e255a 100644
--- a/src/render/SDL_render.c
+++ b/src/render/SDL_render.c
@@ -3680,6 +3680,8 @@ static int SDLCALL SDL_SW_RenderGeometryRaw(SDL_Renderer *renderer,
                 s.y = uv0_[1] * texh;
                 s.w = uv1_[0] * texw - s.x;
                 s.h = uv1_[1] * texh - s.y;
+            } else {
+                s.x = s.y = s.w = s.h = 0;
             }
 
             d.x = xy0_[0];
diff --git a/src/stdlib/SDL_string.c b/src/stdlib/SDL_string.c
index dc47d60d6d45..6b838714579e 100644
--- a/src/stdlib/SDL_string.c
+++ b/src/stdlib/SDL_string.c
@@ -1050,7 +1050,7 @@ int SDL_strncmp(const char *str1, const char *str2, size_t maxlen)
 #if defined(HAVE_STRNCMP)
     return strncmp(str1, str2, maxlen);
 #else
-    int result;
+    int result = 0;
 
     while (maxlen) {
         result = (int)(unsigned char)*str1 - (unsigned char)*str2;
@@ -1061,9 +1061,6 @@ int SDL_strncmp(const char *str1, const char *str2, size_t maxlen)
         ++str2;
         --maxlen;
     }
-    if (!maxlen) {
-        result = 0;
-    }
     return result;
 #endif /* HAVE_STRNCMP */
 }
@@ -1098,7 +1095,7 @@ int SDL_strncasecmp(const char *str1, const char *str2, size_t maxlen)
 #elif defined(HAVE__STRNICMP)
     return _strnicmp(str1, str2, maxlen);
 #else
-    int a, b, result;
+    int a, b, result = 0;
 
     while (maxlen) {
         a = SDL_tolower((unsigned char)*str1);
@@ -1111,9 +1108,6 @@ int SDL_strncasecmp(const char *str1, const char *str2, size_t maxlen)
         ++str2;
         --maxlen;
     }
-    if (maxlen == 0) {
-        result = 0;
-    }
     return result;
 #endif /* HAVE_STRNCASECMP */
 }
diff --git a/src/video/SDL_RLEaccel.c b/src/video/SDL_RLEaccel.c
index d9c81f38819d..1a3ee4a0e4ef 100644
--- a/src/video/SDL_RLEaccel.c
+++ b/src/video/SDL_RLEaccel.c
@@ -175,7 +175,7 @@
         Uint8 *src = from;                                       \
         Uint8 *dst = to;                                         \
         for (i = 0; i < (int)(length); i++) {                    \
-            Uint32 s, d;                                         \
+            Uint32 s = 0, d = 0;                                         \
             unsigned rs, gs, bs, rd, gd, bd;                     \
             switch (bpp) {                                       \
             case 2:                                              \
diff --git a/src/video/SDL_vulkan_utils.c b/src/video/SDL_vulkan_utils.c
index d2f5599ea1ff..2993fc7991a8 100644
--- a/src/video/SDL_vulkan_utils.c
+++ b/src/video/SDL_vulkan_utils.c
@@ -273,7 +273,7 @@ SDL_bool SDL_Vulkan_Display_CreateSurface(void *vkGetInstanceProcAddr_,
         VkDisplayKHR display;
         VkDisplayPlanePropertiesKHR *displayPlaneProperties = NULL;
         VkExtent2D extent;
-        VkDisplayPlaneCapabilitiesKHR planeCaps;
+        VkDisplayPlaneCapabilitiesKHR planeCaps = { 0 };
 
         /* Get information about the physical displays */
         result = vkGetPhysicalDeviceDisplayPropertiesKHR(physicalDevice, &displayPropertiesCount, NULL);