Fix trustStoreType JVM property consultation in SSL connections (#2691)

[Ananya Garg (Ananya2)]

Problem

The JDBC driver was not properly consulting the JVM system property javax.net.ssl.trustStoreType when the trustStoreType connection property was not explicitly set. This affected all SSL connection scenarios where users expected -Djavax.net.ssl.trustStoreType=Windows-ROOT (or other values) to be honored.

Root Cause

The trust manager selection logic in IOBuffer.enableSSL() was missing the standard fallback hierarchy for trustStoreType resolution when entering the KeyStore loading path.

Solution

Added comprehensive JVM system property consultation logic that follows the standard Java property resolution hierarchy:

1. Check connection property trustStoreType
2. If empty, check JVM system property javax.net.ssl.trustStoreType
3. If still empty, use default value "JKS"

Changes

• IOBuffer.java: Added System.getProperty("javax.net.ssl.trustStoreType") fallback logic in lines 1678-1683
• Applies to all SSL connection modes: encrypt=true, encrypt=strict, login-only encryption, etc.
• Maintains backward compatibility and existing explicit property behavior

Testing

• Verified that all encryption modes now properly respect JVM system properties
• Confirmed that explicit connection property values still take precedence
• Validated that default behavior (JKS) is preserved when neither property is set
• Tested with various trustStoreType values including Windows-ROOT, PKCS12, etc.

Impact

• Enables Windows certificate store integration across all SSL connection types
• Restores expected Java standard property consultation behavior
• Improves compatibility with existing deployment scripts and system configurations
• No breaking changes to existing functionality

Fixes #2691

[codecov]

Codecov Report

❌ Patch coverage is 66.66667% with 1 line in your changes missing coverage. Please review.
✅ Project coverage is 51.68%. Comparing base (c8c028f) to head (69b6a6c).
⚠️ Report is 1 commits behind head on main.

Files with missing lines	Patch %	Lines
...in/java/com/microsoft/sqlserver/jdbc/IOBuffer.java	66.66%	0 Missing and 1 partial ⚠️

Additional details and impacted files

@@             Coverage Diff              @@
##               main    #2724      +/-   ##
============================================
+ Coverage     51.66%   51.68%   +0.02%     
+ Complexity     4112     4109       -3     
============================================
  Files           149      149              
  Lines         34240    34242       +2     
  Branches       5718     5719       +1     
============================================
+ Hits          17690    17699       +9     
+ Misses        14110    14103       -7     
  Partials       2440     2440              

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